CN101788968B - Chip select signal spreading method - Google Patents

Abstract

The invention discloses a chip select signal spreading method, which comprises the following steps: selecting a free address space of a system; inputting a signal; performing operation according to a chip select signal spreading algorithm rule; and enabling related peripheral equipment according to the chip select signal. On the basis of not changing a hardcore of the system, the free address space can be used, chip select signals of new hardware are spread besides previous chip select signals of the system, and the peripheral equipment connected with the system previously cannot be influenced. By using the free address space, existing resources can be effectively utilized, and additional cost is not required to be increased. The chip select signal spreading method has strong practicability, hardly increases additional load for the system, can be applied to the field of control signal generation and transmission and is suitable for various baseband chips.

Description

Chip select signal spreading method

Technical field

The present invention relates to a kind of control signal and produce and transmission technology, relate in particular to a kind of chip select signal spreading method.

Background technology

In present electronic product, increasing deviser and user hope when controlling cost, in product, to increase greater functionality.This just requires do not expanding hardware interface in the enhanced system major control chip.With the MTK6223D baseband chip is example, and this system comprises the 1G space, and has divided 2 and have the address space CS0 that is used for chip selection signal, CS1.But only using CS0, CS1 has not only wasted remaining address space, and can only enable 2 external units to these two address spaces.This system just can't accomplish when needs insert more external unit, need in the hardware configuration of product, increase interface.Other baseband chips also have similar problem.

There is following shortcoming at least in above-mentioned prior art:

Waste idle address space, can only insert a spot of external unit, when the expansion hardware interface, must change system platform, increase cost of products, application is not strong, when inserting multiple peripheral hardware, can not increase the equipment that will insert of deleting flexibly.

Summary of the invention

The purpose of this invention is to provide a kind of flexible design, with low cost, practical chip select signal spreading method.

The objective of the invention is to realize through following technical scheme:

Chip select signal spreading method of the present invention, this method may further comprise the steps:

A, the idle address space of selective system;

B, input signal;

C, carry out computing according to chip selection signal expansion algorithm rule;

D, enable associated external equipment according to chip selection signal.

Technical scheme by the invention described above provides can be found out, chip select signal spreading method of the present invention is because the method comprising the steps of: the idle address space of selective system at first; Input signal afterwards; Carry out computing according to chip selection signal expansion algorithm rule then; Enable associated external equipment according to chip selection signal at last.Can on the basis that does not change system core hardware, use idle address space, the chip selection signal of the new hardware of expansion outside the existing chip selection signal of original system, and the peripheral hardware that original system is connected does not have any impact.Use idle address space effectively to utilize and have resource, need not increase extra cost, practical, increase extra load to system hardly.

Description of drawings

Fig. 1 is the principle steps figure of chip select signal spreading method of the present invention;

Fig. 2 is the said baseband chip address space of specific embodiment of the invention partition description figure;

Fig. 3 is the corresponding external unit key diagram of the said former baseband chip address space of the specific embodiment of the invention;

Fig. 4 is the specific embodiment of the invention 1 a said chip internal arithmetic logic key diagram;

Fig. 5 is the specific embodiment of the invention 1 a said chip internal arithmetic logic key diagram;

Fig. 6 is that the specific embodiment of the invention 1 said baseband chip address space is divided the corresponding external unit key diagram in back according to chip select signal spreading method;

Fig. 7 is the specific embodiment of the invention 2 said chip internal arithmetic logic key diagrams;

Fig. 8 is that the specific embodiment of the invention 2 said baseband chip address spaces are divided the corresponding external unit key diagram in back according to chip select signal spreading method;

Fig. 9 is the new address space key diagrams of the specific embodiment of the invention 3 said baseband chips;

Figure 10 is the specific embodiment of the invention 3 said chip internal arithmetic logic key diagrams;

Figure 11 is that the specific embodiment of the invention 3 said baseband chip address spaces are divided the corresponding external unit key diagram in back according to chip select signal spreading method;

Figure 12 is the specific embodiment of the invention 4 said chip internal arithmetic logic key diagrams;

Figure 13 is that the specific embodiment of the invention 4 said baseband chip address spaces are divided the corresponding external unit key diagram in back according to chip select signal spreading method.

Embodiment

Chip select signal spreading method of the present invention, its preferable embodiment is as shown in Figure 1:

This method may further comprise the steps:

A, the idle address space of selective system;

B, input signal;

C, carry out computing according to chip selection signal expansion algorithm rule;

D, enable associated external equipment according to chip selection signal.

The idle address space of system in the said steps A is the idle address space that is not used that system itself provides.Said idle address space can comprise:

System distributed but the address space that do not have to use and/or system has distributed and occupied address space in not have the part of use.

The idle address space of said system can be divided and corresponding corresponding external unit in advance.

Input signal among the said step B can comprise address signal and/or reference signal.

Chip selection signal algorithmic rule among the said step C can comprise one or more in the following rule:

Rule one, chip enable signal 1=address signal 1+ reference signal 1

Chip enable signal 3=address signal 2+ reference signal 1

Rule two, chip enable signal 1=address signal 2+ reference signal 1

Rule three,

Rule four,

Said chip selection signal algorithmic rule can draw chip enable signal through the logical operation of address signal and reference signal.

Said chip enable signal enables the corresponding external unit of ready-portioned in advance address space.

Said external unit can be enabled by the chip enable signal of correspondence.

Chip select signal spreading method according to the invention; Its core technology scheme is: the idle address space of selective system at first; Next uses address signal and reference signal to carry out computing according to chip selection signal expansion algorithm rule, and enables associated external equipment according to chip selection signal.Can on the basis that does not change system core hardware, use idle address space, the chip selection signal of the new hardware of expansion outside the existing chip selection signal of original system, and the peripheral hardware that original system is connected does not have any impact.Use idle address space effectively to utilize and have resource, need not increase extra cost.Chip selection signal algorithmic rule of the present invention is practical, increases extra load to system hardly.The present invention is applied to control signal and produces and transmission field, adapts to multiple baseband chip.

Below through specific embodiment and combine accompanying drawing that the application is carried out detailed description:

With the MTK6223D baseband chip in the cell phone system is example:

External unit receives the enable signal in the address space that baseband chip distributes through the EMI external apparatus interface.In cell phone system, generally need 4 external units at least, promptly need the external unit chip enable signal of 4 independent mutual exclusions.But in MTK6223D, only encapsulate out two idle address spaces.

As shown in Figure 2, CS0, CS1 take the 256M space respectively, and remaining 512M space is non-encapsulated to be gone out.In general cell phone system, CS0, CS1 can enable an external unit respectively;

As shown in Figure 3, the corresponding FLASH of CS0, the corresponding PSRAM of CS1.In this case, insert other equipment again like needs, like LCD, DSP etc. just need take other resources, generate independently chip enable signal, cause the increase of cost.But, CS0, the space among the CS1 still has rest parts not use after being taken by FLASH and PSRAM respectively, and in addition, the non-encapsulated 512M space that goes out also can be divided into CS2, and the idle address space that two of CS3 have the 256M space uses.

In 32 bit address, the 27th and the 28th digit separator CS0 to CS3.

CS0 is 0000 0xxx xxxx xxxx xxxx xxxx xxxx xxxx,

CS1 is 0000 1xxx xxxx xxxx xxxx xxxx xxxx xxxx,

CS2 is 0001 0xxx xxxx xxxx xxxx xxxx xxxx xxxx,

CS3 is 0001 1xxx xxxx xxxx xxxx xxxx xxxx xxxx.

In chip select signal spreading method, can be other address bits that can not exert an influence to other equipment arbitrarily in 32 bit address simultaneously, in this embodiment, use the 23rd with the reference signal of the common computing of address signal, the 24th, the 25th.Be called EA23, EA24, EA25 hereinafter successively.

Specific embodiment 1

Use CS0; The address space that is not taken by FLASH and PSRAM among the CS1 is in order to enable LCD and DSP external unit; But the external unit that can be enabled is not limited in described 4 equipment, corresponding other external unit in other system, and this chip select signal spreading method is suitable equally.

FLASH among CS0 and the CS1 and PSRAM can not take the whole spaces of system for its distribution in some system, these remaining spaces just can be used, and distribute to other external unit.This method can effectively be saved the space, reduces cost.

At this specific embodiment chips internal arithmetic logic such as Fig. 4 and shown in Figure 5; Preferred EA24 is that sheet selects input reference signal; But be not limited to EA24, in different system, can select in 32 bit address any one can not select input reference signal as sheet the address bit that other equipment exerts an influence.In the present embodiment, according to the chip selection signal algorithmic rule, each peripheral hardware corresponding address signal is following:

FLASH：0000?0000?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

LCD： 0000?0001?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

PSRAM：0000?1000?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

DSP： 0000?1001?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

According to the chip internal arithmetic logic, the chip selection signal algorithmic rule is following:

CS_out0＝CS0+EA24

$\mathrm{CS}\_\mathrm{out}1=\mathrm{CS}0+\stackrel{\‾}{\mathrm{EA}24}$

CS_out2＝CS1+EA24

$\mathrm{CS}\_\mathrm{out}3=\mathrm{CS}1+\stackrel{\‾}{\mathrm{EA}24}$

Computing is as shown in Figure 6 after accomplishing, and address space is divided into FLASH and LCD two parts among the former CS0, and address space is divided into PSRAM and DSP two parts among the former CS1.The corresponding FLASH chip selection signal of CS_out0, the corresponding LCD chip selection signal of CS_out1, the corresponding PSRAM chip selection signal of CS_out2, the corresponding DSP chip selection signal of CS_out3.CS_out0 to CS_out3 is the chip enable signal of 4 mutual exclusions, and the external unit that each chip enable signal is corresponding is pre-set can not changing, and can only enable an external unit at one time.Carrying out the chip selection signal expansion in this way can enable same external unit according to a plurality of addresses in the effective address scope.

Specific embodiment 2

Use among the CS1 not the address space that is taken by PSRAM in order to enable LCD and DSP external unit, CS0 is still monopolized by FLASH.The external unit that can be enabled is not limited in described 4 equipment, corresponding other external unit in other system, and this chip select signal spreading method is suitable equally.

Consider that FLASH needs occupation space bigger under some situation; CS0 can only satisfy the space requirement of FLASH; And the PSRAM among the CS1 takes up space very little in some system; Can not take the whole spaces of system for its distribution, these remaining spaces just are used, and distribute to other external unit.This method can effectively be saved the space, reduces cost.

As shown in Figure 7 in this specific embodiment chips internal arithmetic logic; Preferred EA23 and EA24 are that sheet selects input reference signal; But be not limited to EA23 and EA24, in different system, can select in 32 bit address any two can not select input reference signal as sheet the address bit that other equipment exerts an influence.In the present embodiment, according to the chip selection signal algorithmic rule, each peripheral hardware corresponding address signal is following:

FLASH：0000?00xx?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

LCD： 0000?1001?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

PSRAM：0000?1001?0xxx?xxxx?xxxx?xxxx?xxxx?xxxx

DSP： 0000?1001?1xxx?xxxx?xxxx?xxxx?xxxx?xxxx

According to the chip internal arithmetic logic, the chip selection signal algorithmic rule is following:

CS_out0＝CS1+EA24

$\mathrm{CS}\_\mathrm{out}1=\mathrm{CS}1+\stackrel{\‾}{\mathrm{EA}24}+\mathrm{EA}23$

$\mathrm{CS}\_\mathrm{out}2=\mathrm{CS}1+\stackrel{\‾}{\mathrm{EA}24}+\stackrel{\‾}{\mathrm{EA}23}$

Computing is as shown in Figure 8 after accomplishing, and address space is divided into PSRAM among the former CS1, LCD and DSP three parts.The corresponding PSRAM chip selection signal of CS_out0, the corresponding LCD chip selection signal of CS_out1, the corresponding DSP chip selection signal of CS_out2.CS_out0 to CS_out2 is the chip enable signal of 3 mutual exclusions, and the external unit that each chip enable signal is corresponding is pre-set can not changing, and can only enable an external unit at one time.Carrying out the chip selection signal expansion in this way can enable same external unit according to a plurality of addresses in the effective address scope.

Specific embodiment 3

Use CS2; The non-encapsulated idle address space that goes out of CS3 is in order to enable LCD and DSP external unit; CS0, CS1 are still monopolized by FLASH and PSRAM, but the external unit that can be enabled is not limited in described 4 equipment; Corresponding other external unit in other system, this chip select signal spreading method is suitable equally.

FLASH in some system and PSRAM take up space very big; Remaining space can not satisfy the demand of miscellaneous equipment; Though and in baseband chip, only marked off CS0 and two address spaces of CS1, still having the 512M space is idle address space, can distribute to other external unit.If this 512M spatial division is become CS2 and two new address spaces of CS3, as shown in Figure 9, the same with CS0 and CS1, can be new external unit service equally.This method can increase new external apparatus interface under the prerequisite that does not influence the original address space division of baseband chip, effectively save the space, reduces cost.

Shown in figure 10 in this specific embodiment chips internal arithmetic logic; Preferred EA24 and EA25 are that sheet selects input reference signal; But be not limited to EA24 and EA25, in different system, can select in 32 bit address any two can not select input reference signal as sheet the address bit that other equipment exerts an influence.In the present embodiment, according to the chip selection signal algorithmic rule, each peripheral hardware corresponding address signal is following:

FLASH：0000?00xx?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

LCD： 0000?10xx?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

PSRAM：0001?0001?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

Or 0,001 1001 xxxx xxxx xxxx xxxx xxxx xxxx

DSP： 0001?0010?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

Or 0,001 1010 xxxx xxxx xxxx xxxx xxxx xxxx

According to the chip internal arithmetic logic, the chip selection signal algorithmic rule is following:

$\mathrm{CS}\_\mathrm{out}0=\stackrel{\‾}{\mathrm{EA}24}$

$\mathrm{CS}\_\mathrm{out}1=\stackrel{\‾}{\mathrm{EA}25}$

Computing is shown in figure 11 after accomplishing, and address space still is FLASH among the former CS0, and address space is PSRAM still among the former CS1, and the CS2 that newly marks off is LCD, and the CS3 that newly marks off is DSP.The corresponding LCD chip selection signal of CS_out0, the corresponding DSP chip selection signal of CS_out1.CS_out0 to CS_out2 is the chip enable signal of 2 mutual exclusions, and the external unit that each chip enable signal is corresponding is pre-set can not changing, and can only enable an external unit at one time.Carrying out the chip selection signal expansion in this way can enable same external unit according to a plurality of addresses in the effective address scope.

Specific embodiment 4

Use the non-encapsulated idle address space that goes out of CS3 in order to enable LCD and DSP external unit; CS0; CS1 is still monopolized by FLASH and PSRAM; But the external unit that can be enabled is not limited in described 4 equipment, corresponding other external unit in other system, and this chip select signal spreading method is suitable equally.

FLASH in some system and PSRAM take up space very big; Remaining space can not satisfy the demand of miscellaneous equipment; Though and in baseband chip, only marked off CS0 and two address spaces of CS1, still having the 512M space is idle address space, can distribute to other external unit.If this 512M spatial division is become CS2 and two new address spaces of CS3, as shown in Figure 9, the same with CS0 and CS1, can be new external unit service equally.This method can increase new external apparatus interface under the prerequisite that does not influence the original address space division of baseband chip, effectively save the space, reduces cost.

Shown in figure 12 in this specific embodiment chips internal arithmetic logic; Preferred EA24 is that sheet selects input reference signal; But be not limited to EA24, in different system, can select in 32 bit address any one can not select input reference signal as sheet the address bit that other equipment exerts an influence.In the present embodiment, according to the chip selection signal algorithmic rule, each peripheral hardware corresponding address signal is following:

FLASH：0000?0000?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

LCD： 0000?1000?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

PSRAM：0001?1000?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

DSP： 0001?1001?xxxx?xxxx?xxxx?xxxx?xxxx?xxxx

According to the chip internal arithmetic logic, the chip selection signal algorithmic rule is following:

$\mathrm{CS}\_\mathrm{out}0=\stackrel{\‾}{\mathrm{CS}0\·\mathrm{CS}1}+\mathrm{EA}24$

$\mathrm{CS}\_\mathrm{out}1=\stackrel{\‾}{\mathrm{CS}0\·\mathrm{CS}1}+\stackrel{\‾}{\mathrm{EA}24}$

Computing is shown in figure 13 after accomplishing, and address space still is FLASH among the former CS0, and address space is PSRAM still among the former CS1, and the CS3 that newly marks off is LCD and DSP two parts.The corresponding LCD chip selection signal of CS_out0, the corresponding DSP chip selection signal of CS_out1.CS_out0 to CS_out2 is the chip enable signal of 2 mutual exclusions, and the external unit that each chip enable signal is corresponding is pre-set can not changing, and can only enable an external unit at one time.Carrying out the chip selection signal expansion in this way can enable same external unit according to a plurality of addresses in the effective address scope.

Chip select signal spreading method of the present invention; Be not restricted to listed utilization in instructions and the embodiment; It can be applied to various suitable the present invention's field fully; For being familiar with those skilled in the art, can be easy to realize additional advantage and make amendment, therefore under the situation of the spirit of the universal that does not deviate from claim and equivalency range and limited and scope, the examples shown that the present invention is not limited to specific details and illustrates here and describe.

The above; Be merely the preferable embodiment of the present invention, but protection scope of the present invention is not limited thereto, any technician who is familiar with the present technique field is in the technical scope that the present invention discloses; The variation that can expect easily or replacement all should be encompassed within protection scope of the present invention.

Claims (4)

1. a chip select signal spreading method is characterized in that, this method may further comprise the steps:

A, the idle address space of selective system;

B, input signal;

C, carry out computing according to chip selection signal expansion algorithm rule;

D, enable associated external equipment according to chip selection signal;

The idle address space of system in the said steps A is the idle address space that is not used that system itself provides, and the idle address space of said system is divided and corresponding corresponding external unit in advance;

Input signal among the said step B comprises address signal and/or reference signal;

Chip selection signal algorithmic rule among the said step C comprises one or more in the following rule:

Rule one,

Chip enable signal 1=address signal 1+ reference signal 1

Rule two,

Chip enable signal 1=address signal 2+ reference signal 1

Rule three,

Rule four,

Said chip enable signal enables the corresponding associated external equipment of ready-portioned in advance address space.

2. chip select signal spreading method according to claim 1 is characterized in that, said idle address space comprises:

System distributed but the address space that do not have to use and/or system has distributed and occupied address space in not have the part of use.

3. chip select signal spreading method according to claim 1 is characterized in that, said chip selection signal algorithmic rule draws chip enable signal through the logical operation of address signal and reference signal.

4. chip select signal spreading method according to claim 3 is characterized in that, said associated external equipment can only be enabled by the chip enable signal of correspondence.

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