PM7347 datasheet(283/341 Pages) PMC

283 / 341 page

S/UNI®-JET Data Sheet

Released

Proprietary and Confidential to PMC-Sierra, Inc., and for its Customers’ Internal Use

283

Document ID: PMC-1990267, Issue 3

° If OVR = 1, then discards last frame and go to step 1. Overrun causes a reset of FIFO

pointers. Any packets that may have been in the FIFO are lost.

° If COLS = 1, then sets the EMPTY FIFO software flag.

° If PKIN = 1, increments the PACKET COUNT. If the FIFO is desired to be emptied as

soon as a complete packet is received, set the EMPTY FIFO software flag. If the EMPTY

FIFO software flag is not set, FIFO emptying will delayed until the FIFO fill level is

exceeded.

• Starts the processing of FIFO data. Uses the PBS[2:0] packet byte status bits to decide what is

to be done with the FIFO data.

° If PBS[2:0] = 001, discards data byte read in step 3 and sets the LINK ACTIVE software

flag.

° If PBS[2:0] = 010, discards the data byte read in step 3 and clears the LINK ACTIVE

software flag.

° If PBS[2:0] = 1XX, stores the last byte of the packet, decrements the PACKET COUNT,

and checks the PBS[1:0] bits for CRC or NVB errors before deciding whether or not to

keep the packet.

° If PBS[2:0] = 000, stores the packet data.

° If FE = 0 and INTR = 1 or FE = 0 and EMPTY FIFO = 1, goes to step 3 or else clears the

EMPTY FIFO software flag and leaves this interrupt service routine to wait for the next

interrupt.

The link state is typically a local software variable. The link state is inactive if the RDLC is

receiving all-ones or receiving bit-oriented codes which contain a sequence of eight ones. The

link state is active if the RDLC is receiving flags or data.

If the RDLC data transfer is operating in the polled mode, processor operation is exactly as

shown above for the interrupt driven mode, except that the entry to the service routine is from a

timer, rather than an interrupt.

PM7347 Datasheet(PDF) 283 Page - PMC-Sierra, Inc