PM6344 datasheet(222/256 Pages) PMC

222 / 256 page

STANDARD PRODUCT

PMC-Sierra, Inc.

PM6344 EQUAD

PMC-951013

ISSUE 5

QUADRUPLE E1 FRAMER

209

The jitter on the recovered clock is absorbed by the two frame slip buffer in the

elastic store. BRPCM[x], BRSIG[x], and BRFPO[x] are updated on the falling

edge of RCLKO[x].

The framing alignment on BRPCM[x] and BRSIG[x] is still set by the BRFPI

input. However, BRFPI must now be timed with respect to the individual output

clock RCLKO[x] instead of BRCLK for each quadrant of the EQUAD in which

RCLKOSEL is set to logic 1. A possible configuration would have RCLKOSEL

set to logic 1 in only one quadrant and BRFPI timed to that quadrant's RCLKO.

The same RCLKO can then be connected to BRCLK which will be used as the

timing reference for all the other quadrants which will have RCLKOSEL set to

logic 0. Otherwise, if backplane frame alignment is not necessary, RCLKOSEL

can be set to logic 1 in every quadrant and BRFPI should be tied low.

Figure 31 shows the functional waveforms for a configuration where RCLKOSEL

is set to logic 1 in quadrant x. BRFPI and all the backplane outputs are timed to

RCLKO[x].

Figure 31

- Receive Backplane Interface with RCLKOSEL = 1

1 2 345 6 7 8

AB C D

1 2 3 456 78 1 23 4 5 67 8

AB C D

1 23 4 5 67 8 1 2 345 6 7 8

AB C D

Timeslot 31

Timeslot 0

Timeslot 1

Timeslot 16

Timeslot 17

RCLKO[x]

BRFPO[x]

BRPCM[x]

BRSIG[x]

BRFPI

Undefined

It should also be noted that RFP[x] can no longer be sampled by RCLKO[x] since

RCLKO[x] is a smoothed version of the recovered clock, and RFP[x] is timed by

the unsmoothed recovered clock.

BRX2RAIL in the Receive Backplane Options register must be cleared to logic 0

for proper operation. The DJAT Configuration register should be cleared to all

zeros to disable the LIMIT and SYNC bits. Note that the DJAT PLL is no longer

in the transmit path. Therefore, the FIFOBYP bit of the Transmit Interface

Configuration register must be set. to logic 1.

PM6344 Datasheet(PDF) 222 Page - PMC-Sierra, Inc

PM6344 Datasheet(HTML) 222 Page - PMC-Sierra, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL