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STANDARD PRODUCT
PM8315 TEMUX
DATASHEET
PMC-1981125
ISSUE 7
HIGH DENSITY T1/E1 FRAMER WITH
INTEGRATED VT/TU MAPPER AND M13 MUX
PROPRIETARY AND CONFIDENTIAL
203
12.7.2 Direct Access Mode
Direct access mode to the TPSC or RPSC is not used in the TEMUX. However,
direct access mode is selected by default whenever the TEMUX is reset. The
IND bit within the TPSC and RPSC Configuration Registers must be set to
logic 1 after a reset is applied.
12.7.3 Indirect Access Mode
Indirect access mode is selected by setting the IND bit in the TPSC or RPSC
Configuration Register to logic 1. When using the indirect access mode, the
status of the BUSY indication bit should be polled to determine the status of the
microprocessor access: when the BUSY bit is logic 1, the TPSC or RPSC is
processing an access request; when the BUSY bit is logic 0, the TPSC or RPSC
has completed the request.
The indirect write programming sequence for the TPSC (RPSC) is as follows:
1. Check that the BUSY bit in the TPSC (RPSC) μP Access Status Register is
logic 0.
2. Write the channel data to the TPSC (RPSC) Channel Indirect Data Buffer
register.
3. Write RWB=0 and the channel address to the TPSC (RPSC) Channel Indirect
Address/Control Register.
4. Poll the BUSY bit until it goes to logic 0. The BUSY bit will go to logic 1
immediately after step 3 and remain at logic 1 until the request is complete.
5. If there is more data to be written, go back to step 1.
The indirect read programming sequence for the TPSC (RPSC) is as follows:
1. Check that the BUSY bit in the TPSC (RPSC) μP Access Status Register is
logic 0.
2. Write RWB=1 and the channel address to the TPSC (RPSC) Channel Indirect
Address/Control Register.
3. Poll the BUSY bit, waiting until it goes to a logic 0. The BUSY bit will go to
logic 1 immediately after step 2 and remain at logic 1 until the request is
complete.