JP4073301B2 - Information processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an information processing apparatus, and more particularly to an information processing apparatus having a CPU such as a printer or an MFP.
[0002]
[Prior art]
In conventional systems, it is common to boot from a non-volatile memory having a memory bus interface. In this case, any form of a storage medium that can be mounted on or detached from the CPU board may be used. Here, FLASHROM generally used as a boot device is expensive. In addition, when MASKROM is used as a boot device, there is a practical inconvenience such that rewriting cannot be performed. The above problem is particularly noticeable when the program has a large capacity, and the program is generally composed of a small-capacity FLASH ROM and an inexpensive large-capacity low-speed device (such as an HDD).
[0003]
Conventionally, as an information processing apparatus having a configuration for directly executing a program stored in a ROM, a RAM, or the like, it is determined whether or not a memory card is mounted, and if it is mounted, a predetermined area of the memory card is mapped Then, the identification code is read out, the drive on which the file to be mapped exists is determined as RAM, ROM, or memory card based on the read identification code, and the file stored in the determined drive is mapped. What has been disclosed is disclosed.
[0004]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-161857
[Problems to be solved by the invention]
However, the invention described in Patent Document 1 can easily overwrite the RAM file if the designated drive is mapped to the ROM or memory card, so that the OS and various device drivers stored in the RAM can be easily used. The boot ROM is included in the system.
[0006]
The present invention has been made in view of the above-described circumstances, and in an information processing apparatus having an interface unit for detachably mounting a storage medium such as a memory card, it is directly booted from a low-speed device such as a memory card. Thus, the boot ROM can be made unnecessary and a small and inexpensive device is provided.
[0007]
[Means for Solving the Problems]
The invention of claim 1, and can be activated directly from the external storage medium without a memory bus interface, an information processing apparatus having no boot ROM inside, for mounting detachably said external storage medium An interface unit, and a mapping unit that directly maps a program stored in the external storage medium attached to the interface unit to a CPU memory space, the mapping unit after the information processing apparatus is powered on before the end of initialization of the CPU, it is from the external storage medium which was characterized by Rukoto includes an initialization means for performing an initialization process required to read the program.
[0008]
According to a second aspect of the present invention, in the first aspect of the invention, the mapping means assigns a CPU boot vector address included in the CPU memory space to an area of a user data area of the external storage medium. It is.
[0009]
The invention of claim 3 is the invention of claim 1 or 2, characterized in that the external storage medium constructs a FAT system.
[0010]
According to a fourth aspect of the present invention, in any one of the first to third aspects of the present invention, a memory card is used as the external storage medium.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a diagram showing a hardware system configuration example according to an embodiment of the present invention, in which 1 is a memory card, 2 is an information processing device, and 3 is a personal computer (hereinafter referred to as a PC). In FIG. 1, the dotted line frame shows an example of the system configuration of the present invention. The memory card 1 is detachable from the interface unit of the information processing apparatus 2 and is mounted on the information processing apparatus 2. Further, it can be mounted in a card slot of the PC 3 and of course can be accessed. For the memory card 1, for example, a small storage medium such as an SD (Secure Digital) memory card or a memory stick can be suitably used. The present invention can be suitably used for an information processing apparatus having a memory capacity of about 16 to 64 MB.
[0012]
Next, a configuration example of hardware according to the present invention will be described.
FIG. 2 is a block diagram for explaining a configuration example of a controller of the information processing apparatus 2 in the present invention. In the figure, 20 is a controller of the information processing apparatus 2, and the controller 20 includes a CPU 21, a volatile work memory ( RAM) 22, ASIC 23, I / O block 24, card controller 25, and card socket 26. The controller 20 includes a CPU 21, an ASIC 23 in which functions such as memory control and external I / O control are integrated, a readable / writable volatile work memory 22, and a card controller 25. The ROM 27 indicated by the dotted line is a boot memory that is necessary in the conventional system, but is not mounted in the present invention because it can boot directly from the memory card 1 .
[0013]
FIG. 3 is a block diagram for explaining a configuration example of the card controller 25 shown in FIG. 2. The card controller 25 includes a memory bus interface 25a, a protocol conversion unit 25b, an automatic initialization routine 25c, and a card interface 25d. have. The card controller 25 is a block that converts the memory bus interface 25a to the card interface 25d of the memory card 1 and generates a protocol. The memory bus interface 25a is interfaced with a request signal, a memory address, data, a Read / Write signal and an ACK signal. The protocol conversion unit 25b decodes these signals and converts the address (for example, CPU addr: BFC0000 → Card). addr: 800), a protocol is generated (for example, a read command or an access type is specified), and the memory card 1 is interfaced. The protocol conversion unit 25b has an automatic initialization routine 25c in which procedures such as dummy clock output, status acquisition, card register initialization, and the like are set, and card initialization is automatically performed at power-on reset. It is.
[0014]
Embodiments of the card interface 25d include a form in which a card slot dedicated to a memory card is built in the information processing apparatus 2, a form in which a card adapter having a memory card slot is externally connected to the information processing apparatus 2 through various ports, and the like. Can be taken.
[0015]
According to the present invention, since the system can be directly booted from a removable storage medium having no memory interface, a boot ROM is not necessary, and an inexpensive and small system can be configured. In addition, by making the storage medium a general-purpose standard part, availability is improved and sharing with different models such as a personal computer is also possible.
[0016]
FIG. 4 is a diagram for explaining an example of a memory map of the memory card 1. In this example, the format of the memory card 1 is a FAT system. Therefore, when storing the program, it is stored from the head address of the user data area according to the format specification. In this case, in order to maintain the FAT system, as shown in FIG. 4, it is necessary to assign the CPU Boot vector Address (CPU boot vector address) to the Card User Start Address (or Start Address + Offset). For example, in the address conversion process, the CPU address: BFC00000 (H) may be converted to 800 (H), which is the leading address of the card address. For example, 200 (H) may be taken as BFC00000 (H) → 1000 (H). This offset can be set arbitrarily. The conversion process from the CPU address to the card address is performed in hardware by the protocol conversion unit 25b. In this way, the FAT system can be maintained by placing the CPU boot vector address in the user area of the FAT system.
[0017]
According to the present invention, since the storage medium corresponds to the FAT system even though it is a boot ROM, the storage medium can be accessed even in a different model such as a personal computer that supports the FAT system.
[0018]
FIG. 5 is a flowchart for explaining the operation flow of the card controller 25 shown in FIG. First, after the power is turned on, the card controller 25 is reset before a CPU reset is released after a predetermined time has elapsed (step S1), and the card is automatically initialized (step S2). Here, although details are omitted in the flowchart, dummy clock output for card initialization, status acquisition, card register initialization, and the like are performed according to the procedure. Thereafter, when the CPU reset is released (step S3), the CPU 21 reads the data of the boot vector (address BFC0000 in this example). The protocol conversion unit 25b determines whether a request (Read or Write) has been received (step S4). If the received request is a read, the CPU address (Addr = BFC00000) is received (step S5) and the read is performed. A command is issued (step S6).
[0019]
Next, the protocol conversion unit 25b converts the CPU address (Addr = BFC00000) into a card address (Addr = 800) (step S7), performs address conversion and protocol generation according to the card, and then accesses the card. To do. When the protocol conversion unit 25b receives data (CData = 5555) at a predetermined address (step S8), the protocol conversion unit 25b makes an ACK response together with the data (DATA = 5555) received on the CPU side (step S9).
[0020]
If the request received in step S4 is write (Write), the flow is basically the same as in the read case, but an ACK response is made when write data is received. That is, a CPU address (Addr = BFC01000) is received (step S10), an ACK response is made at this point (step S11), and a write command is issued (step S12).
[0021]
Next, the protocol conversion unit 25b converts the CPU address (Addr = BFC01000) into a card (write) address (Addr = 1800) (step S13), and after performing address conversion and protocol generation according to the card, Access the card. The protocol conversion unit 25b writes CData = AAAA as write data (step S14). In step S4, when there is no request (in the case of NO), a request waiting state is entered in step S4.
[0022]
【The invention's effect】
According to the present invention, in an information processing system having an interface unit for detachably mounting a storage medium such as a memory card, a boot ROM can be made unnecessary by directly booting from a low-speed device such as a memory card, A small and inexpensive system can be provided.
Furthermore, since the memory card can be automatically initialized (dummy clock output, status acquisition, card register initialization, etc.) by the mapping means, the CPU stores the boot vector data immediately after the memory card initialization. Can be read out.
[Brief description of the drawings]
FIG. 1 is a diagram illustrating a hardware system configuration example according to an embodiment of the present invention.
FIG. 2 is a block diagram for explaining a configuration example of a controller of the information processing apparatus according to the present invention.
FIG. 3 is a block diagram for explaining a configuration example of a card controller shown in FIG. 2;
FIG. 4 is a diagram for explaining an example of a memory map of a memory card.
FIG. 5 is a flowchart for explaining an operation flow of the card controller shown in FIG. 3;
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Memory card, 2 ... Information processing apparatus, 3 ... Personal computer, 20 ... Controller, 21 ... CPU, 22 ... Volatile work memory, 23 ... ASIC, 24 ... I / O block, 25 ... Card controller, 25a ... Memory Bus interface, 25b ... protocol conversion unit, 25c ... automatic initialization routine, 25d ... card interface, 26 ... card socket, 27 ... ROM.

Claims (4)

An information processing apparatus that can be directly activated from an external storage medium that does not have a memory bus interface, and that does not have an activation ROM therein,
Wherein a and the external storage medium interface unit for detachably mounting and the mapping means for the external storage medium mounted on the interface unit is directly mapped to program stored in the CPU memory space,
It said mapping means, initialization before the end of the information processing apparatus after power-on of a CPU, characterized Rukoto includes an initialization means for performing an initialization process required to read the program from the external storage medium Information processing apparatus.   The information processing apparatus according to claim 1, wherein the mapping unit assigns a CPU boot vector address included in the CPU memory space to an area of a user data area of the external storage medium.   3. The information processing apparatus according to claim 1, wherein the external storage medium constructs a FAT system.   4. The information processing apparatus according to claim 1, wherein a memory card is used as the external storage medium.

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