RELEASED
PM4354 COMET-QUAD
DATASHEET
PMC-1990315
ISSUE 6
FOUR CHANNEL COMBINED E1/T1/J1
TRANSCEIVER / FRAMER
PROPRIETARY AND CONFIDENTIAL TO PMC-SIERRA, INC. AND FOR ITS CUSTOMERS’ INTERNAL USE
145
a logic 1, extended superframe alignment is chosen and BTFP[x] does pulse (FPMODE
logic 0) or expects to be pulsed (FPMODE logic 1) every 24 frames on the first frame bit of
the extended superframe.
This bit is ignored when in E1 mode or in T1 mode when FPTYP is a logic 0.
FPTYP:
The frame pulse type (FPTYP) bit determines the type of frame pulse on BTFP[x]. When
FPTYP is a logic 0, basic frame alignment is chosen and frame pulses occur every frame.
When FPTYP is a logic 1, multiframe alignment is chosen.
In T1 mode with multiframe alignment, BTFP[x] does pulse (FPMODE logic 0) or expects to
be pulsed (FPMODE logic 1) every 12 or 24 frames as determined by the ESF_EN bit.
In E1 mode, with multiframe alignment when FPMODE is a logic 0, as an output BTFP[x]
pulses once every 16 frames to indicate both CRC and signaling multiframe alignment. When
BTFP[x] is configured as an input, it must be brought high to mark bit 1 of frame 1 of every 16
frame signaling multiframe and brought low following bit 1 of frame 1 of every 16 frame CRC
multiframe.
To properly initialize the transmit HDLC controllers in basic frame alignment mode (FPTYP is
logic 0), multiframe alignment (FPTYP is logic 1) must be configured for at least one
multiframe (i.e., for at least one multiframe period in frame pulse master mode or for at least
one input frame pulse in frame pulse slave mode). After this initialization, the FPTYP can be
set to any desired value.
In Transmit Clock Slave: H-MVIP mode, FPTYP must be programmed to logic 0.
FPMODE:
The frame pulse mode (FPMODE) bit determines whether BTFP[x] is an input or an output.
When FPMODE is a logic 0, frame pulse master mode is selected and BTFP[x] is an output.
When FPMODE is a logic 1, frame pulse slave mode is selected and BTFP[x] is an input.
Frame pulse master mode cannot be used with transmit backplane clock rates greater than
2.048 MHz.
In Transmit Clock Slave: H-MVIP mode, FPMODE must be programmed to logic 1.