SLASEC8B February 2017 – January 2019 PGA460-Q1
The command field is the second field in every frame sent by the master device. The command field contains instructions about what to do with and where to send the data that is transmitted to a particular PGA460-Q1 device. The command field can also instruct the PGA460-Q1 device to send data back to the master device during a read operation. The number of data fields to be transmitted is also determined by the command in the command field. Figure 24 shows the format of the command field.
In the PGA460-Q1 device, the last 3-bits of the command field are reserved for UART address information. The address information in the command field is compared to the UART_ADDR parameter in the EEPROM memory where the UART address is programmed. Upon receiving the command field, the PGA460-Q1 device checks if the self-address matches the received address and if it matches, the device executes on the received command. If the address does not match, the device disregards the received frame. For improved communication efficiency, common broadcast commands are defined where the PGA460-Q1 device executes regardless of the address in the command field. For these commands and all UART commands, see Table 3.
The factory preprogrammed address for the PGA460-Q1 device is 0.