ADLINK CoreExpress-ECO2 - Manual (Page 12)

4 DETAILED DESCRIPTION OF SMC COMMAND CODES
4.1 Set/Clear Watchdog-timer
After Start-Up the Watchdog is disabled or loaded with a startup value (Type II Watchdog) from the
Flash memory. This command must be used to (re-)load or to clear the Timeout of the Watchdog-
timer. The timeout value is given in seconds and has a 16-bit (two byte wide) size. So the Timeout
of the Watchdog can be set to 1-65535 seconds. 0 disables the Watchdog.
START SMC_addr ACK command ACK length ACK MSB_byte ACK LSB_byte ACK STOP
Table 4.1.1 SMC receiver format of the Watchdog-timer Command Code
ITEM DESCRIPTION
START SM-bus start condition
SMC_addr 0x50 (8-bit)
ACK SM-bus acknowledge condition generated by receiver
command 0x20 = “Set/Clear Watchdog-timer” Command code
length 0x02 = 2 Bytes data length
MSB_byte High-byte of Timeout-value in seconds
LSB_byte Low-byte of Timeout-value in seconds
STOP SM-bus stop condition
Table 4.1.2 Explanation of Table 4.1.1