Datasheet

____________________________________________________ DS34T101, DS34T102, DS34T104, DS34T108
92 of 366
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 d
escribes the pool and
queue registers.
Figure 10-54. TDM-to-CPU Flow