DG-IRMCK203 Datasheet, PDF (35/67 Pages) International Rectifier – Application Developer’s Guide

IRMCK203 Application Developer’s Guide
RS-232 Register Read Access
A register read operation consists of a command/address byte, byte count and checksum. When the IRMCK203
receives the command, it validates the checksum and transmits the register data to the host.
Command / Address Byte
Byte Count
Register Read Operation
Checksum
Command Acknowledgement Byte Register Data (Byte Count bytes)
Checksum
Register Read Acknowledgement (transfer OK)
Command Acknowledgement Byte
Checksum
Register Read Acknowledgement (error)
The following example shows a command sequence sent from the host to the IRMCK203 requesting four bytes of read
register data:
0xA0
Read operation beginning at offset 0x20 (high-order bit selects read operation)
0x04
Requested data byte count is 4
0xA4
Checksum
A good reply from the IRMCK203 might appear as follows:
0x20
Read completed OK at offset 0x20
0x11
Data byte 1
0x22
Data byte 2
0x33
Data byte 3
0x44
Data byte 4
0xCA
Checksum
An error reply to the command would have the following format:
0xA0
Read at offset 0x20 completed in error
0xA0
Checksum
RS-232 Timeout
The IRMCK203 receiver includes a timer that automatically terminates transfers from the host to the IRMCK203 after
a period of 32 msec.
RS-232 Transfer Examples
The following example shows a normal exchange executing a register write access.
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