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VLYNQ 2.0 Packet Format

Table A-3. Packet Format (10-bit Symbol Representation) Description

Field

Value

Description

PKTTYPE[3:0]

 

This field indicates the packet type.

 

0000

Reserved

 

0001

Write with address increment.

 

0010

Reserved

 

0011

Write 32-bit word with address increment.

 

0100

Reserved

 

0101

Configuration write with address increment.

 

0110

Reserved for extended command indicator (cmd2).

 

0111

Interrupt

 

1000

Reserved

 

1001

Read with address increment.

 

1010

Reserved

 

1011

Read 32-bit word with address increment.

 

1100

Reserved

 

1101

Configuration read with address increment.

 

1110

Reserved for VLYNQ version 2.0 and later.

 

1111

Read response for all VLYNQ versions.

ADRMASK[3:0]

 

Indicates which byte of the address is included in the packet. Only address bytes that have changed

 

 

since the previous address will be included. Each bit corresponds to one byte of address.

BYTECNT[7:0]

 

Byte count. This field indicates the total number of bytes in the packet. This field is only included for

 

 

write, read, and configuration packet types. All other packet types have fixed lengths and do not

 

 

require this field.

ADDRESS[7:0]

 

Address byte 0. This byte is included only if ADRMASK[0] is set to 1. If ADRMASK[0] is cleared to 0,

 

 

assume this byte is equal to bits 7:0 of the previous address. Read response packets do not include

 

 

this field.

ADDRESS[15:8]

 

Address byte 1. This byte is included only if ADRMASK[1] is set to 1. If ADRMASK[1] is cleared to 0,

 

 

assume this byte is equal to bits 15:8 of the previous address. Read response packets do not include

 

 

this field.

ADDRESS[23:16]

 

Address byte 2. This byte is only included if ADRMASK[2] is set to 1. If ADRMASK[2] is cleared to 0,

 

 

this assume this byte is equal to bits 23:16 of the previous address. Read response packets do not

 

 

include this field.

ADDRESS[31:24]

 

Address byte 3. This byte is only included if ADRMASK[3] is set to 1. If ADRMASK[3] is cleared to 0,

 

 

assume this byte is equal to bits 31:24 of the previous address. Read response packets do not

 

 

include this field.

DATA

 

Data payload. The maximum data payload size is limited to sixteen 32-bit words to allow it to fit in the

 

 

RX FIFO.

EOP

 

End of packet indicator, /T/.

The CMD2 bit is only included in the packet, if the packet type indicates extended command (PKTTYPE = 0110).

Use configuration packet types to remotely access VLYNQ module registers. The configuration packet types do not depend on control register bit settings.

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VLYNQ Protocol Specifications

SPRUE36A –September 2007

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Texas Instruments VLYNQ Port manual Field Value Description