JPS6345602A - Electronic engine controller - Google Patents

Abstract

PURPOSE:To ensure the correct replacement of port data by reading these port data and rewriting partly these data with a new data. CONSTITUTION:When a port 1 is used for output, the 8-bit data equal to that of the port 1 is stored in a RAM. The port is identified by its address and therefore the RAM storing area (address) of the 8-bit data is set opposite to the port address. When the data on the port 1 are replaced, an access is given to a RAM address and the 8-bit data is read out to an accumulator. Then the corresponding bits of the accumulator are replaced with the new data. Then the 8-bit data on the accumulator can be written to the port 1 and the RAM. Thus the 8-bit data equal to that of the port 1 are stored in the RAM. In such a way, the correct output port data can be partly rewritten with no influence of noises, load, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electronic engine control device equipped with a micro combinator, and particularly to a method for outputting data to its output port.

[Conventional technology]

As shown in FIG. 1, an electronic engine control unit (ECU) equipped with a microcomputer receives the output S + of the opening sensor of the throttle valve 12, the output S2 of the intake pressure sensor 14, the rotation signal S3 from the distributor 18, and the exhaust gas. The sensor 22 output (021 degrees) S4, the cooling water temperature S5 is taken in, the ignition signal S6 is sent to the igniter coil 20, the ISC signal S7 is sent to the idle speed control (ISC) valve 26, and the fuel injector A fuel injection signal S8 is output to the (injector) 16 to control the engine.

As shown in Fig. 2, this control unit ECU includes a microcomputer unit (MCt+), a read-only memory ROM,
, random access memory RAM.

Consists of an analog-to-digital converter A/D, input and output interface (INT). Throttle opening S1, intake pressure S2, cooling water temperature S5, intake air temperature S9, etc. are analog signals, so they are input to the A/D, converted into digital signals, and input to the MCU. Since the rotation signal s3 and the on/off signals of the idle switch SIO, air conditioner switch Sll, and scooter switch S12 are digital signals, they are directly input to the MCU via the input interface without going through the A/D. Ignition signals S6, T are output from the output ink face.
An SC signal S7, a fuel injection signal Sa, and others (ignition advance control, diagnostic code output, etc.) s15 are output.

The input/output interface is also called an I10 port, and the MCU of this example has 41 I10 ports as shown in FIG. Three of these ports, 1, 3.4, are 8-bit ports, and the remaining port 2 is a 5-bit port. 8-bit boat 3 has two control terminals SC.
I, SC2 are attached. Each boat has DDR (data
When "1" is written to this port, the port is used for output, and when "O" is written, the port is used for input.The output cover sofa is three-state, and becomes high impedance when used for input. Note that PTM is a programmable timer unit, SCI is a serial communication interface, and MUX is a multiplexer.

[Problem that the invention seeks to solve]

Thus, a port is a plurality of bits, and each bit represents an individual signal and is independent of each other, but writing/reading to and from a port is performed in units of a plurality of bits. Once data is written to the output port, it remains in the same state until the next write is performed. Since each bit of multi-bit port data is independent, rewriting (updating) often involves partial rewriting, such as rewriting one bit, and rewriting all bits is rather rare. For partial rewriting, the MPU reads all the points of the boat, rewrites the corresponding bits with new data, and writes all the updated bits to the boat.

Incidentally, in engine control, the load end is often an L (inductance) load such as a solenoid or a motor.

If it is an L-type load, a flyback voltage will occur when turning on and off, and the corresponding bit of the boat will be affected by this and 1" will change to 0".
(H level becomes L level). In addition, the noise environment is poor (ignition noise may mix in and cause data read errors.Also, if an open collector type transistor switch is connected to the output port bit,
When this bit is at H level and the transistor is on, when reading this bit, it is at the level of VBE (base-emitter voltage), so the MPU judges it to be at L level (MCU input H level). V engineering u (#2.OV
) >VBE (#0.7 V).

L when it is 0.8 V or less).

This updating method of reading all bits of a boat, rewriting some of the bits with new data, and then writing all the updated bits to the boat again is likely to cause bit errors. Since the vote data remains in the same state until the next update, the above bit error will persist.

The present invention aims to improve these points and make it possible to rewrite correct boat data.

[Failure to solve the problem]

In the present invention, the same multi-bit data written to the boat is stored in the memory (RAM, ROM). When updating the boat data, the data in the memory is read to obtain multi-bit data, the bits to be rewritten therein are rewritten with new data, and the updated multi-bit data is written to the port.

[Effect]

In this way, the boat data is read, part of it is rewritten with new data, and the whole thing is not rewritten to the relevant port, so it is not affected by port load or mixed noise, and the correct boat data is updated. can be done.

〔Example〕

It is easy to prepare the same data as port I data in the storage means. For example, if boat 1 is used for output in Figure 3,
The same 8-bit data as this 8-bit data is stored in the RAM. Since a boat is identified by an address, the RAM storage area (address) of the 8-bit data is associated with the port address. To update the data of port 1, access the RAM address above, read the 8-bit data to the accumulator (not shown, but an arithmetic unit in the MPU), replace the corresponding bit of the accumulator with new data, and then update the corresponding bit. Just write the 8-bit data of the accumulator to port 1 and RAM. By this writing, the same 8-bit data as the 8-bit data of the port is stored in the RAM.

Therefore, when performing the next update, the same operation can be repeated.

Instead of storing the port data itself in the RAM, data from which the port data can be derived may be stored in the RAM. For example, when controlling a stepper motor, its excitation pattern is fixed, so it is sufficient to store information indicating one of them.

Figure 4 shows the case where the Steshiba motor has 4 phases, 41 to 4
4 is the excitation winding for each phase. 31 to 34 are output sofas (inverters) connected to each bit of the output port.
When the relevant bit is at H level, L level output is generated,
The excitation winding is excited by being supplied with current through a path between the battery power supply +B, the excitation winding, and the output end of the buffer. In addition, the cover sofa 35, 36. . . . are for other operating terminals, and 51 is the aforementioned open collector type transistor switch. Inverters 31, 32.・
. . . may be of the type of switch 51.

There are various types of drive types for the Steshiba motor, but in this example, two-phase excitation is used. To explain with reference to FIG. 6, at time point (count) 1, φ1=φa=L.

φ2=φy=H, which appears in the 4 bits of the output port, and when the outputs of the buffers 31 and 34 and the outputs of H132 and 33 become L, the windings 42 and 43 are excited. Volume 1!
41-44 are arranged at 90° intervals, so that the rotor faces midway between windings 42 and 43. Next point in time (count)
2, φ] = φ2 = L, φ3 = ψa = H, therefore, the windings 43 and 44 are excited, and the rotor rotates 90'' to point midway between the windings 43 and 44 (the same applies hereafter). , at time 1°2, . . . , the rotor rotates in 90” steps.

If this excitation pattern is tabulated, it will be as follows.

Table 1 Each count is 0, 1. Excitation pattern φ
4~φI, that is, 0011.0110. RO
M's addresses ADR0, 1, . . . (this is the sum of the appropriate starting address 6 RO plus the counter count value), and the counter count value (count) o.

1, . . . If this is read out, an excitation pattern can be obtained. Therefore, what is stored in RAM is the current count (0
. In this example, the excitation pattern is 4 bits, so if the 8-bit port is used alone, the remaining 4 pins may be set to O. If you want to use the remaining 4 bits for other purposes, store them in RAM (for other purposes, you can store them in the RAM).
-j If W is small, it may be obtained by reading the output port) This will be ORed with the ROM read data.

FIG. 7 shows a circuit for reading port output data.

In this example, the output port consists of flip-flops 61 and 64 and buffers 62 and 63. At reset, the DDR (flip-flop 64) is cleared and the port is an input port. After resetting, when 1 is written to DDR, the buffer 62 becomes active and the write signal WS
The data on the data bus is taken into the flip-flop and outputted through the buffer 62. When the read signal R8 activates the buffer 63, it outputs the data at the output of the buffer 62 and sends it to the data bus. In this way, the boat data is read, and the read data is determined by the voltage level of the boat output terminal, and therefore the buffer 62
If the load (output port load) is a pure resistance, etc., it is the output logic of the output port itself. However, as mentioned above, if there is noise when reading the boat, or when directly driving a transistor, the boat output terminal The voltage level and boat output data do not necessarily match.

When reversing the stepper motor, it is sufficient to count down the counter and output 3, 2, 1, 0, 3, 2 degrees, and so on. When changing from normal rotation to reverse rotation, as shown in Figure 8, repeat the same rotation once and then count down.

FIG. 7 shows a flowchart for controlling the stepper motor. As shown in the figure, if it is not the drive timing of the stepper motor, this routine is exited, and if it is the drive timing, it is checked whether the step is changed or not, if it is No, this routine is also exited, and if YES, it is checked whether it is reversed. If YES, exit this routine. This is the 6th
As shown in the figure, when changing from forward rotation to reverse rotation, the same state is
It will continue. If it is not reversed (even if it is reversed, if the same state is taken for one step as described above, it will no longer be reversed), check whether it is a forward direction, and if YES, add 1 to the count value C3TP of the counter indicating the step pattern. is the new value, and it is added to the ROM start address A D Ro that stores the step pattern to calculate the corresponding R.
The OM is read to obtain a step pattern 1100 and the like.

If it is not the forward direction, it is set as C3TP-1, and the ROM is accessed with this to obtain the corresponding step pattern.

The 4-bit step pattern obtained in this way is set in a predetermined accumulator AccA, and the remaining 4-bit data M is taken out from the RAM etc. in which it is stored.
Add (or) the data using AccA to create 8-bit data, and write it to the relevant boat.

The remaining 4 bits are changed as shown in FIG. First, it is checked whether the output should be changed to the remaining 4 focus points, and if No, this routine exits, and if YES, it is next checked whether to output 1. If YES, RA storing 4 bits A
Access M, set read data to AccA, and perform addition (OR). For example, A=OOOO10
000 (the last of the remaining 4 bits is 1), and the RAM data is 11000000, then AccA=1101000
Set to 0. If the check is NO to output 1, then it is still R.
AM continues and its data (set to 11010000)
is set to A ccA, and the inverted bit A of bit A (
If you want to set the last of the remaining 4 bits to 0, 11101111)
(results in 11000000). This calculation result A ccA is stored in RAM, and ADRo +
C5TPT: Accesses the ROM to obtain the pattern data and sends it to the accumulator AccB. The logical sum of AccA and AccB is written to the boat.

This method of changing output port data based on RAM allows accurate update of output data without being affected by noise on the wiring on the boat exit side, kW of load, etc.; The above effect can also be obtained by waiting to update until new data is determined for all bits, and rewriting the output port data all at once when new data for all bits is determined. The processing procedure in this case is shown in FIG. Compute bit A, set it in memory or register M, then compute bit B,
Set it to M, calculate the last bit H in the same way, add cents to M, and the contents of M HG...
...Write A to the output port.

〔Effect of the invention〕

As explained above, according to the present invention, it is possible to partially rewrite correct output port data without being affected by noise, load, etc., and it is extremely effective for use in electronic engine control devices and the like.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram showing the details of the engine control system, Fig. 2 is a block diagram showing the configuration of the ECLI, Fig. 3 is a block diagram showing the configuration of the processor, and Fig. 4 is an example of the load on the output port. FIG. 5 is an explanatory diagram of input/output ports, FIG. 6 is a drive waveform diagram of the stencil motor, and FIGS. 7 to 9 are flowcharts showing processing procedures. In the drawing, ECU is an electronic engine control unit, MCU is its processor, S II S 21 ...... is sensor output, S 6 + S 7. . . . is an output signal to the operating end. Applicant Fujitsu Ten Ltd. Representative Patent Attorney Minoru Aoyagi Figure 1 Figure 2 Figure 4 Forward rotation 1 Reverse count + 23012301'+03210 3
2 Figure 6 Jar Figure 7 Figure 8

Claims (1)

[Claims] In an electronic engine control device in which a microcomputer takes in sensor outputs indicating the status of each part of the engine and outputs a signal to an operating end to an output port, the same as the multi-bit data output to the output port. A memory (RAM, ROM) in which data is stored, and when rewriting some bits of the multi-bit data, read the memory to obtain the multi-bit data, rewrite the relevant bits with new data, and An electronic engine control device comprising means for writing bit data to an output port.