SLOS757G December 2011 – March 2020 TRF7962A
The digital part of the transmitter is a mirror of the receiver. The settings controlled the ISO Control register (0x01) are applied to the transmitter just like the receiver. In the TRF7962A default mode (ISO Mode), the TRF7962A automatically adds all the special signals like start of communication, end of communication, SOF, EOF, parity bits and CRC bytes.
The data is then coded to modulation pulse levels and sent to the RF output stage modulation control unit. Just like with the receiver, this means that the external system MCU only must load the FIFO with data and all the microcoding is done automatically, again saving the firmware developer code space and time. Additionally, all the registers used for transmit parameter control are automatically preset to optimum values when a new selection is entered into the ISO Control register (0x01).
The FIFO must be reset before starting any transmission with direct command 0x0F.
If the data length is longer than the FIFO, the external system MCU is warned when the majority of data from the FIFO was already transmitted by sending and interrupt request with flag in IRQ register to indicate a FIFO low or high status. The external system should respond by loading next data packet into the FIFO.
At the end of a transmit operation, the external system MCU is notified by interrupt request (IRQ) with a flag in the IRQ register (0x0C) indicating TX is complete (example value = 0x80).