2.7.1 TX Overview

The ATA8510/15 comprises one physical transmission path. However, it is possible to store configurations for two paths (path A and path B) to comply with the RX configuration options. If individual settings are possible for the two paths, this is marked with a small “x” in the subsequent sections. When starting a transmit mode, the user has to chose one single path configuration to be used for transmission.

The transmit mode (TXMode) can be activated automatically after power-on if preselected by the operating mode (OPM) bits of the EEPROM variable eepTrxConf.sysStartConfig or it can be manually started with the SPI command “Set System Mode”.

If TXMode is to be automatically activated after power-on, the eepTrxconf.sysStartConfig EEPROM variable must be correctly configured. For the proper service/channel configuration as well as optional tune and calibration settings, see sEEPromTrxConfig eepTrxConf.


Address	Name	Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
0x0019	sysStartConfig	RF_CAL	ANT_TUNE	VCO_TUNE	IDLEModeSelector	—	TMDEN	OPM[1:0]

TXMode can also be activated by using the SPI command “Set System Mode” if the operating mode (OPM) bits in the systemModeConfig parameter are set to “0b01”. The required service/channel configuration as well as additional settings such as VCO tuning are part of the SPI command. For more information, see Set System Mode.


Name	Bit 7	Bit 6	Bit 5	Bit 4	Bit 3	Bit 2	Bit 1	Bit 0
systemModeConfig	RF_CAL	ANT_TUNE	VCO_TUNE	IDLEModeSelector	—	TMDEN	OPM[1:0]
serviceChannelConfig	enaPathB	enaPathA	ch[1:0]		—	ser[2:0]

The TXMode start-up is aborted if

Path A and path B are set simultaneously in the service/channel configuration
Path A and path B are cleared simultaneously in the service/channel configuration
An AVCC low interrupt has occurred

If one of these cases occurs, TXMode is not started and the system error flag is set with the error code DEBUG_ERROR_CODE_INVALID_OPM_SWITCHING. The system is, then, switched to IDLEMode.

TXMode is separated into TXMode(transparent) and TXMode(buffered), selectable by the transparent mode data enable (TMDEN) bit in the systemModeConfig parameter of the “Set System Mode” SPI command or in the eepTrxConf.sysStartConf.TMDEN EEPROM variable. If TXMode(transparent) is selected, the data are modulated from pin18/TMDI directly.

In TXMode(buffered) the data have to be written to internal FIFOs via the SPI before they are modulated. The following figure gives an overview of the data flow in transparent and buffered mode. A detailed description is given in the sections below.

TXMode is controlled mainly by the sequencer state machine (SSM), which is located in the hardware and performs the start-up procedure. The firmware does the configuration and control of the SSM. The following figure shows the entire TXMode flow.

After TXMode is activated, the firmware initializes the registers based on the settings in the selected service/channel configuration and configures the sequencer state machine for TXMode. If an RF calibration is selected, a temperature calibration of the XTO is carried out based on the latest available temperature value. A temperature measurement itself is not performed.

It is possible to configure TXMode with or without VCO tuning and with or without antenna tuning at TXMode start-up. For more information, see the “Set System Mode” SPI command.

Start-up is controlled by the firmware via a software watchdog timer (Timer2 is used). If there is no hardware response or an error message from the SSM, the firmware sets the SYS_ERR bit in the events.system event byte. The error code is stored in the SRAM variable debug, which contains the firmware error code (debug.errorCode) and the SSM error code (debug.ssmErrorCode). For more information, see Error Codes.

After a successful start-up, the command ready (CMD_RDY) event “TX Ready” is set if enabled in the event configuration. Now, data can be provided via the TMDI pin in TXMode(transparent).

In TXMode(buffered) the software waits for the correct fill levels of the SFIFO and the DFIFO. After both fill levels are reached, the firmware starts the TX modulator on the hardware side. The TX modulator controls the whole transmission and signals a transmission complete flag via IRQ to the firmware. After the transmission completes, the TXMode restarts or shuts down depending on what is specified in the eepServices.txSysEventx.TX_Ending EEPROM variable.

After a shutdown of TXMode, the system returns to IDLEMode.