Motorola MPC860 PowerQUICC User Manual page 594

Part V. The Communications Processor Module
The TSA supports two independent TDM channels, each with independent receive and
transmit routing and independent sync pulses and clocks. Thus the TSA can support four,
independent, half-duplex TDM sources, two receiving and two sending, using four sync
inputs and four input clocks; see Figure 21-3.
TDMa Tx Sync
TDMa Rx Sync
MPC860
TDMa
TSA
TDMb
TDMb Tx Sync
TDMb Rx Sync
NOTE: SCCs can receive on one TDM channel and send on another; see SCC2 and SCC3 above.
In addition to TDM channel programming, the TSA supports up to four strobe outputs
controlled on a bit or byte basis. These strobes are completely independent from the
channel routing used by the SCCs and SMCs. The strobes are useful for interfacing to other
devices that do not support the multiplexed interface or for enabling/disabling three-state
I/O buffers in a multi-transmitter system. (Note that the open-drain option on the TXDx
pins to support multiple transmitters is programmed in the parallel I/O block; see
Chapter 34, ÒParallel I/O Ports.Ó) The strobes can also generate output waveforms for such
applications as stepper motor control.
The TSA routing is programmed in a 512-byte, core-accessible SI RAM located in the
internal register section of the MPC860 separate from the dual-port RAM. The SI RAM
contains a total of 128 32-bit entries: the Þrst 64 entries are for programming receive
21-6
TDMa Tx Clk
SCC2 SMC1
TDMa Tx
TDMa Rx Clk
TDMa Rx
TDMb Tx Clk
SCC3
TDMb Tx
TDMb Rx Clk
TDMb Rx
Figure 21-3. Dual TDM Channel Example
MPC860 PowerQUICC UserÕs Manual
SCC2
SCC3
SCC4
SCC2
SMC1
MOTOROLA