DS2155 datasheet(169/262 Pages) DALLAS

169 / 262 page

DS2156

169 of 262

24.4 Fractional T1/E1 mode

In fractional T1/E1 mode, the framer is programmed to provide a gapped clock by setting CCR3.4 and

CCR3.5 = 0. The gapped clocks are synchronous with RCLK and TCLK. The UTOPIA block is

programmed to use the clock and ignore the sync signals by setting U_TCR2.1 and U_RCR2.1 = 1. In

this mode, the user can program the clock to be active during any time slot or group of time slots by using

the transmit and receive fractional channel-select function in the per-channel pointer register (PCPR). See

Section 5 for details on using this feature. In T1 mode, the F-bit is automatically gapped. In E1 mode, the

user must program the clock to be gapped during TS0 and/or TS16 if desired.

Table 24-A. UTOPIA Clock Mode Configuration

MODE

U_TCFR.0

U_RCFR.0

CCR3.4

CCR3.5

U_TCR2.3

U_TCR2.1 U_RCR2.1

COMMENTS

Full T1

mode, F-bit

position

gapped

Clear-channel

operation is not

available in T1

mode

Full E1

mode, TS0

and TS16

gapped

Full E1

mode, clear-

channel

(transmit)

—

Transmit framer

must be set to TS0

pass-through mode

E1TCR1.7 = 1 and

transmit-signaling

insertion disabled

Full E1

mode, clear-

channel

(receive)

Method #1

—

Full E1

mode, clear-

channel

(receive)

Method #2

—

Use PCPR and

PCDR1–PCDR4

registers to make

all receive channels

active

Fractional T1

mode

Use PCPR and

PCDR1–PCDR4

registers to select

active transmit and

receive channels

Fractional E1

mode

Use PCPR and

PCDR1–PCDR4

registers to select

active transmit and

receive channels

DS2155 Datasheet(PDF) 169 Page - Dallas Semiconductor

DS2155 Datasheet(HTML) 169 Page - Dallas Semiconductor

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