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FALC
56
PEF 2256 H/E
E1 Registers
User’s Manual
Hardware Description
278
DS1.1, 2003-10-23
CMR2.IRSP = 1:
Internally generated frame synchronization pulse sourced by
the DCO-R circuitry. The pulse is active low for one 2.048 MHz
period.
0010 = RMFB: Receive Multiframe Begin (Output)
Marks the beginning of every received multiframe or optionally
the begin of every CAS multiframe begin (active high).
0011 = RSIGM: Receive Signaling Marker (Output)
Marks the time slots which are defined by register RTR(4:1) of
every frame on port RDO.
0100 = RSIG: Receive Signaling Data (Output)
The received CAS multiframe is transmitted on this pin. Time
slot on RSIG correlates directly to the time slot assignment on
RDO.
0101 = DLR: Data Link Bit Receive (Output)
Marks the S
a
-bits within the data stream on RDO.
0110 = FREEZE: Freeze Signaling (Output)
The freeze signaling status is active high by detecting a
loss-of-signal alarm, or a loss of CAS frame alignment or a
receive slip (positive or negative). It stays high for at least one
complete multiframe after the alarm disappears. Setting
SIC2.FFS enforces a high on pin FREEZE.
0111 = RFSP: Receive Frame Synchronous Pulse (Output)
Marks the frame begin in the receivers synchronous state. This
marker is active low for 488 ns with a frequency of 8 kHz.
1001 = GPI: General Purpose Input
1010 = GPOH: General Purpose Output High
1011 = GPOL: General Purpose Output Low
1100 = LOS: Loss of Signal Output (status of FRS0.LOS)
XPC(3:0)
Transmit multifunction Port Configuration
The multifunction ports XP(A to D) are bidirectional. After Reset these
ports are configured as inputs. With the selection of the pin function
the In/Output configuration is also achieved. Each of the four different
input functions (SYPX, XMFS, XSIG, TCLK) may only be selected
once. No input function must be selected twice or more. SYPX and
XMFS should not be selected in parallel. Register PC1 configures
port XPA, while PC2
→
port XPB, PC3
→
port XPC and PC4
→
port
XPD.