Texas Instruments TLV1562 manual The DSP Serial Port, DSP Serial Port Signals and Registers

The DSP Serial Port

5 The DSP Serial Port

The buffered serial port provides direct communication with serial I/O devices and consists of six basic signals and five registers. The DSP internal serial port operation section discusses the registers.

The six signals are:

•BCLKX - The serial transmit clock. This signal clocks the transmitted data from the BDX terminal to the DIN terminal of the TLC5618A.

•BCLKR - The serial receive clock. This signal clocks data into the DSP BDR terminal. Since the DAC does not send any information back to the DSP, this signal is not important.

•BDX - Data transmit. From this terminal the DSP transmits 16-bit data to the DIN terminal of the TLC5618A.

•BDR - Data receive – not in use

•BFSX - Frame sync transmit. This signal frames the transmit data. The DSP begins to transmit data from BDX on the falling edge of BFSX and continues to transmit data for the next 16 clock cycles from the BCLKX terminal. The BFSX signal is applied to the TLC5618A CS terminal.

•BFSR - Frame sync receive. This signal frames the receive data. The DSP begins to receive data on the falling edge of BFSR and continues to recognize valid data for the following 16 clocks from BCLKR. This signal is not important for this application.

Table 5 lists the serial port pins and registers.

Table 5. DSP Serial Port Signals and Registers

PINS	DESCRIPTION	REGISTERS	DESCRIPTION
BCLKX	Transmit clock signal	BSPC	Serial port control register
BCLKR	Receive clock signal	BSPCE	extended BSPC
BDX	Transmitted serial data signal	BDXR	Data transmit register
BDR	Received serial data signal	BDRR	Data receive register
BFSX	Transmit frame synchronization signal	BXSR	Transmit shift register
BFSR	Receive frame synchronization signal	BRSR	Receive shift register
		AXR	Buffer start location
		BKX	Buffer size

For this application the DSP buffered serial port is programmed as the master, so the BCLKX output is fed to the BCLKR terminal and the BFSX output is fed to the BFSR terminal.

10SLAA040