TDM Power Saving
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
19-31
5.
Clear the AMS bit by writing a 1 to the AMS bit in the TDMxASR.
6.
Repeat steps 3–5 until you read the same value from the ASD field for 20 consecutive
times. At this time the ASD value is valid and can be used to configure the TDM
receiver or transmitter.
7.
Clear the AME bit in the TDMxACR to disable the Adaptation Machine.
8.
Configure the receiver or transmitter according to the following parameters:
— ASD value.
— Number of active links.
— Channel size.
— SYN
19.3 TDM Power Saving
The MSC8144E TDMs use the stop mode of different clocks to save power. Each TDM has three
clock domains: transmit serial, receive serial, and the CLASS64 clock. The transmit serial clock
is not supplied to the TDM module when the transmitter is disabled, that is, the
TDMxTCR[TEN] bit and the TDMxTSR[TENS] are both clear. The receive serial clock is not
supplied to the TDM module when the receiver is disabled, TDMxRCR[REN] bit and
TDMxRSR[RENS] bit are both clear. The CLASS64 clock automatically stops when the TDM is
disabled, that is, both transmitter and receiver are disabled. In addition, the TDM registers get the
CLASS64 clock only at reset or during an access.
19.4 Channel Activation
The TACT and RACT bits in the Transmit/Receive Channel Parameter n Registers (see
page 19-62 and page 19-63) are enabled during the receiver/transmitter operation to control the
channel activation. If the TACT/RACT bit is clear, the channel is not active. Otherwise, it is
active. The procedure for activating an inactive receive channel (C) is as follows:
1.
Verify that the active (RACT) bit of the channel is clear.
2.
Write the initialization value to the channel locations in the receive TDM local memory.
The receive local memory contains 1, 2, 4, 8, 16, or 32 buffers so that each buffer contains
8 bytes per channel. The location of channel C in buffer B is the 8 bytes that start at
(256 / (RNB + 1)
×
B + C)
×
8. (See Section 19.2.3, TDM Data Structures, on page
19-13). For example, if the number of buffers is four, the SC3400 core should write the
initialization value to all four receive buffers. Initializing the receive TDM local memory
prevents invalid data from being received by the channel buffer in the main memory.
3.
Set the TDMxRCPRC[RACT] bit (C indicates the channel number).
The procedure for activating an inactive transmit channel (C) is as follows:
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...