SLOS743M August 2011 – March 2020 TRF7970A
PRODUCTION DATA.
Table 6-19 summarizes the command codes.
COMMAND CODE | COMMAND | COMMENTS |
---|---|---|
0x00 | Idle | |
0x03 | Software initialization | Same as Power on Reset |
0x04 | Perform RF collision avoidance | Does not function as expected. See the TRF7970A Errata for details. |
0x05 | Perform response RF collision avoidance | Does not function as expected. See the TRF7970A Errata for details. |
0x06 | Perform response RF collision avoidance (n = 0) | Does not function as expected. See the TRF7970A Errata for details. |
0x0F | Reset FIFO | |
0x10 | Transmission without CRC | |
0x11 | Transmission with CRC | |
0x12 | Delayed transmission without CRC | |
0x13 | Delayed transmission with CRC | |
0x14 | End of frame and transmit next time slot | Used for ISO/IEC 15693 only |
0x16 | Block receiver | |
0x17 | Enable receiver | |
0x18 | Test internal RF (RSSI at RX input with TX off) | |
0x19 | Test external RF (RSSI at RX input with TX on) |
The command code values from Table 6-19 are substituted in Table 6-20, bits 0 through 4. Also, the most-significant bit (MSB) in Table 6-20 must be set to 1. (Table 6-20 is same as Table 6-11, shown here again for easy reference).
BIT | DESCRIPTION | BIT FUNCTION | ADDRESS | COMMAND |
---|---|---|---|---|
B7 | Command control bit | 0 = Address
1 = Command |
0 | 1 |
B6 | Read/Write | 0 = Write
1 = Read |
R/W | 0 |
B5 | Continuous address mode | 1 = Continuous mode | R/W | 0 |
B4 | Address/Command bit 4 | Adr 4 | Cmd 4 | |
B3 | Address/Command bit 3 | Adr 3 | Cmd 3 | |
B2 | Address/Command bit 2 | Adr 2 | Cmd 2 | |
B1 | Address/Command bit 1 | Adr 1 | Cmd 1 | |
B0 | Address/Command bit 0 | Adr 0 | Cmd 0 |
The MSB determines if the word is to be used as a command or address. The last two columns of Table 6-20 show the function of each bit, depending on whether address or command is written. Command mode is used to enter a command resulting in reader action (initialize transmission, enable reader, and turn reader on or off).