Datasheet

____________________________________________________ DS34S101, DS34S102, DS34S104, DS34S108

Rev: 032609 75 of 198

10.6.11.11

TDM to CPU Flow

The payload-type machines identify the destination of their packets according to the per-bundle configuration.

Upon getting the first byte of a packet in a bundle destined to the CPU, the machine needs a buffer to store the

packet. It therefore checks whether a buffer is available in the TDM-to-CPU pool. If the pool is empty, the machine

discards the current data. If a buffer is available, the machine stores the packet payload in the buffer and then adds

the buffer pointer to the TDM-to-CPU queue. The CPU polls this queue to look for packets that need to be

processed, gets the buffer pointer, and reads the packet from the SDRAM. After processing the packet, the CPU

closes the loop by returning the pointer to the TDM-to-CPU pool.

The TDM-to-CPU pool and queue can contain up to 128 pointers each. Section 11.4.6 describes the pool and

queue registers.

Figure 10-54. TDM-to-CPU Flow

AAL1

HDLC

SDRAM

DATA

TDMoP BLOCK

RAW