STANDARD PRODUCT
PM4351 COMET
DATA SHEET
PMC-1970624
ISSUE 10
COMBINED E1/T1 TRANSCEIVER
PROPRIETARY AND CONFIDENTIAL
366
Figure 35
- Concentration Highway Interface Timing, Example 1
BRCLK
BRFP
BRPCM
bit 0 TS 0
bit 1 TS 0
bit 2 TS 0
bit 3 TS 0
bit 4 TS 0
bit 5 TS 0
bit 6 TS 0
bit 7 TS 0
1
2
3
4
5
6
7
8
9
10
11
12
bit 7 TS 31
bit 6 TS 31
bit 5 TS 31
CER = 3
bit 0 TS 1
CHI timing is configured by setting the BOFF_EN bit of the Receive Backplane
Configuration register to a logic 1. In Figure 35, FE is set to logic 0 so that BRFP
is sampled on the falling edge of BRCLK. DE is set to logic 1 so that BRPCM is
updated on the rising edge of BRCLK. CMS is set to logic 0 so that the clock
rate is equal to the data rate. BOFF[2:0] is set to 'b000 so that the transmit clock
edge (CET) is equal to 3 (as determined by the table in the register description of
BOFF[2:0]) and BRPCM is updated 3 clock edges after BRFP is sampled.
TSOFF is set to 'b0000000 so that there is no time slot offset.
Figure 36
- Concentration Highway Interface Timing, Example 2
BRCLK
BRFP
BRPCM
bit 0 TS 0
bit 1 TS 0
bit 2 TS 0
1
2
3
4
5
6
7
8
9
10
11
12
bit 7 TS 31
bit 6 TS 31
bit 5 TS 31
CER = 8
Don't Care
Don't Care
Don't Care
Don't Care
Don't Care
CHI timing is configured by setting BOFF_EN to a logic 1. In Figure 36, FE is set
to logic 1 so that BRFP is sampled on the rising edge of BRCLK. DE is set to
logic 1 so that BRPCM is updated on the rising edge of BRCLK. CMS is set to
logic 1 so that the clock rate is equal to two times the data rate. BOFF[2:0] is set
to 'b001 so that the transmit clock edge (CET) is equal to 8 (as determined by
the table in the register description of BOFF[2:0]) and BRPCM is updated 8 clock
edges after BRFP is updated. TSOFF is set to 'b0000000 so that there is no
time slot offset.