Serial Interface
MPC885 PowerQUICC Family Reference Manual, Rev. 2
20-6
Freescale Semiconductor
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 20-3.
Figure 20-3. Dual TDM Channel Example
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, “Parallel I/O Ports
.”) 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 MPC885 separate from the dual-port RAM. The SI RAM contains a total of 128 32-bit
entries: the first 64 entries are for programming receive routing, and the second 64 are for transmit routing.
The entries define the number of bits or bytes to be routed to and from the SCCs or SMCs and also control
external strobes.
TDMa Tx
TDMa Rx
TDMa Tx Clk
TDMa Tx Sync
SMC1
SCC3
TDMa
TSA
SCC2 SMC1
SCC2
TDMa Rx Clk
TDMa Rx Sync
NOTE: SCCs can receive on one TDM channel and send on another; see SCC2 and SCC3 above.
TDMb Tx
TDMb Rx
TDMb Tx Clk
TDMb Tx Sync
SCC2
SCC3
SCC4
TDMb Rx Clk
TDMb Rx Sync
TDMb
MPC885
Summary of Contents for PowerQUICC MPC870
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Page 118: ...MPC885 Overview MPC885 PowerQUICC Family Reference Manual Rev 2 1 20 Freescale Semiconductor ...
Page 158: ...The MPC8xx Core MPC885 PowerQUICC Family Reference Manual Rev 2 3 18 Freescale Semiconductor ...
Page 288: ...MPC885 PowerQUICC Family Reference Manual Rev 2 III 4 Freescale Semiconductor ...
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Page 1090: ...UTOPIA Interface MPC885 PowerQUICC Family Reference Manual Rev 2 43 8 Freescale Semiconductor ...
Page 1312: ...Byte Ordering MPC885 PowerQUICC Family Reference Manual Rev 2 A 8 Freescale Semiconductor ...
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Page 1370: ...MPC880 MPC885 PowerQUICC Family Reference Manual Rev 2 E 4 Freescale Semiconductor ...
Page 1386: ...Revision History MPC885 PowerQUICC Family Reference Manual Rev 2 I 2 Freescale Semiconductor ...