PM7375-SC datasheet(161/430 Pages) PMC

161 / 430 page

PM7375 LASAR-155

DATA SHEET

PMC-931127

ISSUE 6

LOCAL ATM SAR & PHYSICAL LAYER

PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC., AND FOR ITS CUSTOMERS’ INTERNAL USE

145

continuously in the payload pointer. When a logic zero is written to this bit

position, the normal pattern (0110B) is inserted in the payload pointer.

PLD:

The PLD bit controls the loading of the pointer value contained in the TPOP

Arbitrary Pointer Registers. Normally, the TPOP Arbitrary Pointer Registers are

written to set up the arbitrary new pointer value and a logic one is then written to

this bit position to load the new pointer value.

If a legal value (i.e. 0 • pointer value • 782) is transferred from the TPOP

Arbitrary Pointer Registers, the transmit payload pointer will immediately change

to the corresponding byte position. If a value greater than 782 is transferred, the

payload pointer remains unchanged.

This bit is automatically cleared after the new payload pointer has been

loaded. This bit has no effect if the FIXPTR bit of the Master Control register is a

logic 1.

SOS:

The SOS bit controls the stuff opportunity spacing between consecutive SPE

positive or negative stuff events. When SOS is a logic zero, stuff events may be

generated every frame as controlled by the PSE and NSE register bits described

above. When SOS is a logic one, stuff events may be generated at a maximum

rate of once every four frames.

FTPTR:

The force transmit pointer bit (FTPTR) enables the insertion of the pointer value

contained in the TPOP Arbitrary Pointer Registers into the transmit stream for

diagnostic purposes. This allows upstream payload mapping circuitry to continue

functioning normally and a valid SPE to continue to be generated, although it is

unlikely to be extracted by far end circuitry which should be in a loss of pointer

state. If FTPTR is set to logic 1, the APTR[9:0] bits of the TPOP Arbitrary Pointer

Registers are inserted into the H1 and H2 bytes of the transmit stream. At least

one corrupted pointer is guaranteed to be sent. If FTPTR is a logic 0, a valid

pointer is inserted.

Reserved:

The reserved bit must be programmed to logic zero for proper operation.

PM7375-SC Datasheet(PDF) 161 Page - PMC-Sierra, Inc