SPI Command Opcode

A SPI transaction starts with a command opcode. SPI slave disregards commands different than opcodes defined in the Table xx-yy.

Table - SPI Command Opcodes

Command	Opcode 1st Byte	Opcode 2nd Byte	Description
RREG	0000_0000b	xxxx_xxxxb	Read the register at address xxxx_xxxxb
WREG	0010_0000b	yyyy_yyyyb	Write the register at address yyyy_yyyyb. The data is the 16-bit that follows the command.
RTKABCQT	0100_0000b	0000_0000b	Read Track A, Track B, Track C and Qwantum Token in burst mode.
RTKBQT	0110_0000b	0000_0000b	Read Track B and Qwantum Token in burst mode.
RTKA	1000_0000b	0000_0000b	Read Track A data in burst mode.
RTKC	1010_0000b	0000_0000b	Read Track C data in burst mode.
RST	1101_1111b	1111_1111b	Reset all device but SPI slave interface.

Read Register Command - RREG

Read register command (RREG) is used to read register values defined in the register map. The Opcode 1st byte is 0000_0000b. The Opcode 2nd byte “xxxx_xxxxb” defines the register address to be read. The SPI chip select should be SSELn=0 for the duration of the command.

Note: The auto-increment address feature has been removed since the register map has just a few registers and there is no real advantage in using the auto-increment address feature.

Read Register Command - RREG

Write Register Command - WREG

Write register command (WREG) is used to write registers defined in the register map. The Opcode 1st byte is 0010_0000b. The write data is 16 bits in width and is provided by the SPI master at the end of the 16 bit Command Opcode. The Opcode 2nd byte “yyyy_yyyyb” defines the register address to be written. The SPI chip select should be SSELn=0 for the duration of the command.

Note: The auto-increment address feature has been removed since the register map has just a few registers and there is no real advantage in using the auto-increment address feature.

Write Register Command - WREG

Read Track A, Track B, Track C Data and Qwantum Token - RTKABCQT

Read Track A and Track B and Track C and Qwantum Token (RTKABCQT) is used to read, in burst mode, Track A, Track B, Track C and Qwantum Token stored in the RAM. The SPI chip select should be SSELn=0 for the duration of the command. If SSELn goes to 1 before the end of the burst read, then a new RTKABCQT command will re-start the burst mode from the first address of the memory and not from the last memory address read from the previous RTKABCQT command. The SPI slave transfers

(1+44+44+44+24)=157 words (Nb=2512 bits) if Qwantum Token Extended mode is disabled or (1+44+44+44+96)=229 words (Nb=3664 bits) if the Qwantum Token Extended mode is enabled. The transfer takes place if SSELn=0 and if SCLK is provided by the SPI master for Nb periods. If the SPI master does not stop SCLK after the last read word, then the SPI slave sets MISO=0.

The RTKABCQT command is valid only when the FSM is in the EXTRACT state. If the SPI master sends the RTKABCQT command when the FSM is not in EXTRACT state, then the SPI slave will disregard the command.

Read Track A, Track B, Track C and Qwantum Token Command - RTKABCQT

Read Track B Data and Qwantum Token - RTKBQT

Read Track B and Qwantum Token (RTKBQT) is used to read, in burst mode, Track B and Qwantum Token stored in the RAM. The SPI chip select should be SSELn=0 for the duration of the command. If SSELn goes to 1 before the end of the burst read, then a new RTKBQT command will re-start the burst mode from the first address of the memory and not from the last memory address read from the previous RTKBQT command. The SPI slave transfers (1+44+24)=69 words (Nb=1104 bits) if Qwantum Token Extended mode is disabled or (1+44+96)=141 words (Nb=2256 bits) if the Qwantum Token Extended mode is enabled. The transfer takes place if SSELn=0 and if SCLK is provided by the SPI master for Nb bits. If the SPI master does not stop SCLK after the last read word, then the SPI slave sets MISO=0.

The RTKBQT command is valid only when the FSM is in the EXTRACT state. If the SPI master sends the RTKBQT command when the FSM is not in EXTRACT state, then the SPI slave will disregard the command.

Read Track B and Qwantum Token - RTKBQT

Read Track A Data - RTKA

Read Track A Data (RTKA) is used to read, in burst mode, Track A data stored in the RAM. The SPI chip select should be SSELn=0 for the duration of the command. If SSELn goes to 1 before the end of the burst read, then a new RTKA command will re-start the burst mode from the first address of the memory and not from the last memory address read from the previous RTKA command. The SPI slave transfers (1+44)=45 words (Nb=720 bits) if SSELn=0 and if SCLK is provided by the SPI master for Nb periods.

If the SPI master does not stop SCLK after the last read word, then the SPI slave sets MISO=0.

The RTKA command is valid only when the FSM is in the EXTRACT state. If the SPI master sends the RTKA command when the FSM is not in EXTRACT state, then the SPI slave will disregard the command.

Read Track A Command – RTKA

Read Track C Data - RTKC

Read Track C Data (RTKC) is used to read, in burst mode, Track C data stored in the RAM. The SPI chip select should be SSELn=0 for the duration of the command. If SSELn goes to 1 before the end of the burst read, then a new RTKC command will re-start the burst mode from the first address of the memory and not from the last memory address read from the previous RTKC command. The SPI slave transfers (1+44)=45 words (Nb=720 bits) if SSELn=0 and if SCLK is provided by the SPI master for Nb periods. If the SPI master does not stop SCLK after the last read word, then the SPI slave sets MISO=0.

The RTKC command is valid only when the FSM is in the EXTRACT state. If the SPI master sends the RTKC command when the FSM is not in EXTRACT state, then the SPI slave will disregard the command.

Read Track C Command - RTKC

Reset - RST

Reset (RST) is used to reset all components in the ASIC but SPI slave interface. The SPI slave interface is under reset when SSELn=0.

Reset Command - RST