Datasheet

DS21455/DS21458 Quad T1/E1/J1 Transceivers
78 of 269
13. I/O PIN CONFIGURATION OPTIONS
Register Name:
IOCR1
Register Description:
I/O Configuration Register 1
Register Address:
01h
Bit # 7 6 5 4 3 2 1 0
Name RSMS RSMS2 RSMS1 RSIO TSDW TSM TSIO ODF
Default 0 0 0 0 0 0 0 0
Bit 0/Output Data Format (ODF).
0 = bipolar data at TPOSO and TNEGO
1 = NRZ data at TPOSO; TNEGO = 0
Bit 1/TSYNC I/O Select (TSIO).
0 = TSYNC is an input
1 = TSYNC is an output
Bit 2/TSYNC Mode Select (TSM). Selects frame or multiframe mode for the TSYNC pin.
0 = frame mode
1 = multiframe mode
Bit 3/TSYNC Double-Wide (TSDW) (T1 Only). (Note: This bit must be set to zero when IOCR1.2 = 1 or when
IOCR1.1 = 0.)
0 = do not pulse double-wide in signaling frames
1 = do pulse double-wide in signaling frames
Bit 4/RSYNC I/O Select (RSIO). (Note: this bit must be set to zero when ESCR.0 = 0.)
0 = RSYNC is an output
1 = RSYNC is an input (only valid if elastic store enabled)
Bit 5/RSYNC Mode Select 1 (RSMS1). Selects frame or multiframe pulse when RSYNC pin is in output mode. In input
mode (elastic store must be enabled) multiframe mode is only useful when receive signaling re-insertion is enabled.
0 = frame mode
1 = multiframe mode
Bit 6/RSYNC Mode Select 2 (RSMS2).
T1 Mode: RSYNC pin must be programmed in the output frame mode (IOCR1.5 = 0, IOCR1.4 = 0).
0 = do not pulse double-wide in signaling frames
1 = do pulse double-wide in signaling frames
E1 Mode: RSYNC pin must be programmed in the output multiframe mode
(IOCR1.5 = 1, IOCR1.4 = 0).
0 = RSYNC outputs CAS multiframe boundaries
1 = RSYNC outputs CRC-4 multiframe boundaries
Bit 7/RSYNC Multiframe Skip Control (RSMS). Useful in framing format conversions from D4 to ESF. This function is not
available when the receive-side elastic store is enabled. RSYNC must be set to output multiframe pulses (IOCR1.5 = 1 and
IOCR1.4 = 0).
0 = RSYNC will output a pulse at every multiframe
1 = RSYNC will output a pulse at every other multiframe