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8xC196EA microcontroller user's manual.1998.pdf
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8XC196EA USER’S MANUAL

17.6.1 SDU RISM Data Transfer

The structure of a data transfer is an 8-bit command byte followed by a specific number of data bytes, which are determined by the command instruction register, SDU_COM. With the RISM data transfer, after you load the RISM command, address, and data registers needed into the code RAM, the last byte loaded must command the SDU to issue the interrupt instruction. After the RISM responds to the interrupt request and executes the command, the most-significant bit of the RISM command byte (located at 400H) will be set to indicate that the RISM has completed the command. The command byte of the RISM must be polled to determine the status of the operation. (Refer to Table 17-5 and Table 17-6 for RISM data transfer command setups.)

17.6.1.1SDU RISM Data Transfer Before

The following table (Table 17-5) shows what needs to be entered into each code RAM location before an interrupt is generated to execute each command.

Table 17-5. Before RISM Command Execution

RISM Command

400H

401H

402H

403H

404H

405H

 

 

 

 

 

 

 

RISM_IDLE

00H

 

 

 

 

 

 

 

READ_BYTE

01H

ADDR(L)

ADDR(M)

ADDR(H)

 

 

 

 

 

 

 

READ_WORD

02H

ADDR(L)

ADDR(M)

ADDR(H)

 

 

 

 

 

 

 

WRITE_BYTE

03H

ADDR(L)

ADDR(M)

ADDR(H)

DATA(L)

 

 

 

 

 

 

 

WRITE_WORD

04H

ADDR(L)

ADDR(M)

ADDR(H)

DATA(L)

DATA(H)

 

 

 

 

 

 

 

GO

05H

 

 

 

 

 

 

 

HALT

06H

 

 

 

 

 

 

 

READ_NEXT_BYTE

11H

 

 

 

 

 

 

 

READ_NEXT_WORD

12H

 

 

 

 

 

 

 

WRITE_NEXT_BYTE

13H

DATA(L)

 

 

 

 

 

 

 

WRITE_NEXT_WORD

14H

DATA(L)

DATA(H)

 

 

 

 

 

 

 

— indicates unused address location

17-12

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