DATA SHEET
PMC-920702
ISSUE 5
PM8313 D3MX
M13 MULTIPLEXER
Pin Name
TOHEN
TOHFP
TOHCLK
TCLK
TPOS/
TDAT
Type Pin No. Function
Input
Output
18 The transmit overhead insertion (TOHEN)
signal controls the insertion of DS3 overhead
bits from the TOH input. When TOHEN is high,
the associated overhead bit in the TOH stream
is inserted in the transmitted DS3 frame. When
TOHEN is low, the DS3 overhead bit is
generated and inserted internally. TOHEN is
sampled on the rising edge of TOHCLK.
15 The transmit overhead frame position (TOHFP)
signal may be used to align the individual
overhead bits in the transmitted overhead data
stream, TOH, to the DS3 M-frame. TOHFP is
high during the X1 overhead bit position in the
TOH stream. TOHFP is updated on the falling
edge of TOHCLK.
Output
14 The transmit overhead clock (TOHCLK) cycles
once per overhead bit. TOHCLK is nominally a
526 kHz clock. TOHFP is updated on the falling
edge of TOHCLK. TOH, and TOHEN are
sampled on the rising edge of TOHCLK.
Output
2 The transmit clock (TCLK) provides timing for
circuitry downstream of the DS3 transmitter of
the D3MX. TCLK is nominally a 44.736 MHz,
50% duty cycle clock.
Output
3 The transmit positive pulse (TPOS) signal
represents the positive pulses transmitted on
the B3ZS-encoded line when configured for
dual-rail operation. TPOS is updated on the
falling edge of TCLK by default but may be
enabled to be updated on the rising edge of
TCLK.
The transmit data output (TDAT) signal
represents a unipolar DS3 output stream when
configured for single rail operation. TDAT is
updated on the falling edge of TCLK by default
but may be enabled to be updated on the rising
edge of TCLK.
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