Rism Command Descriptions - Intel 8XC196NT User Manual

When a receive interrupt occurs, the RISM checks the data value and the DLE flag. If the data
value is greater than 1FH or if the DLE flag is set, the received byte is considered data and is
stored in the DATA register (58H). Each time new data is received, the DATA register is shifted
left by eight bits. If the value is between 00H and 1FH and the DLE flag is clear, the received byte
is considered a command. Commands are stored in the CHAR register (56H). After it executes
each command, the RISM resumes Monitor_Pause, except where otherwise noted.
To access a particular address, you must first send the address across the serial port as data. Send
it one byte at a time, with the high byte first (the address is always assumed to be 16 bits). The
RISM stores the address data in the DATA register. Now you must transfer the address from the
DATA register to the ADDR register (5CH) by sending the DATA_TO_ADDR command (0AH).

15.10.5 RISM Command Descriptions

Table 15-14 lists and describes the RISM commands. The following sections provide examples.
Value Command
00H SET_DLE_FLAG
02H TRANSMIT
04H READ_BYTE
PROGRAMMING THE NONVOLATILE MEMORY
Table 15-14. RISM Command Descriptions
Sets the DLE flag in bit 0 of the MODE register (57H) to tell the RISM that the next
byte on the serial port is data that should be loaded into the DATA register (58H).
The flag is cleared as soon as the byte is read.
Transmits the low byte of the DATA register to the serial port through the CHAR
register, shifts the DATA register right (long) by eight bits, and increments ADDR
by one.
ADDR
Before command 22
After command 22
Puts the contents of the (byte) memory address pointed to by the ADDR register
into the low byte of the DATA register.
ADDR
Before command 22
After command 22
Description
DATA
14 7A 2F 80
15 00 7A 2F
DATA
14
14
SBUF_TX
67
80 67
Memory Addr.
2215 2214
80 67
67 80 67
15-35