DS3171/DS3172/DS3173/DS3174
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PIN NAME
TYPE
PIN DESCRIPTION
This signal can be inverted.
Receive Overhead Start Of Frame
ROHSOFn
: When the port framer is configured for one of the DS3 or E3 framing
modes this signal is used to mark the start of a DS3 or E3 overhead sequence on the
ROHn pins. In T3 mode, the first X-bit is marked. In G.751 E3 mode, the first bit of the
FAS word is marked. In G.832 E3 mode, the first bit of the FA1 byte is marked. The
sequence starts on the same high to low transition of the ROHCLKn clock that this
signal is high. This signal is updated at the same time as the ROHCLKn signal
transitions high to low.
This signal can be inverted.
DS3/E3 Serial Data Overhead Interface
Transmit Line Clock Input
TCLKIn
: This clock is typically used for the reference clock for the TSOFIn, TSERn,
and TSOFOn / TDENn signals but can also be used as the reference for the TPOSn /
TDATn and TNEGn signals. This clock is not used when the part is in loop time mode
or the CLAD clocks are used as the transmit clock source. (
PORT.CR3
.CLADC)
This input signal can be inverted.
o
DS3: 44.736 MHz +20 ppm
o
E3: 34.368 MHz +20 ppm
Transmit Start Of Frame Input
See
Table 10-20.
TSOFIn
: This signal can be used to align the start of the DS3 or E3 frames on the
TSERn pin to an external signal. In SCT modes, the TSOFIn signal can be used to
align the start of frame signal position on the TSERn/TOHn
Pin to the rising edge of a signal on this pin. The signal edge does not need to occur
on every frame and can be tied high or low. The signal is sampled on the positive
clock edge of the referenced clock pin if the clock pin signal is not inverted, otherwise
it is sampled on the falling edge of the clock. The signal is typically referenced to the
TCLKIn transmit clock input pins, but it can be referenced to the TLCLKn, TCLKOn,
RCLKOn and RLCLKn clock pins.
This signal can be inverted.
Transmit Serial Data
TSERn
: When the port framer is configured for either the DS3 or E3 SCT modes, this
pin is used as the source of the DS3/E3 payload data. When the port is configured for
a clear channel mode, this pin is used as the source of the DS3/E3 data signal. The
signal is sampled on the positive clock edge of the referenced clock pin if the clock
pin signal is not inverted, otherwise it is sampled on the falling edge of the clock. The
signal is typically referenced to the TCLKIn transmit clock input pins, but it can be
referenced to the TLCLKn, TCLKOn / TGCLKn, RCLKOn and RLCLKn clock pins
This signal can be inverted.
o
DS3: 44.736 Mbps +20ppm
o
E3: 34.368 Mbps +20ppm
Transmit Clock Output / Gapped Clock
See
Table 10-22.
TCLKOn
: When the port is configured for unframed SCT or framed SCT modes and
TCLKOn is selected, this clock output is enabled. This clock is the same clock as the
internal framer transmit clock. This clock is typically used for the reference clock for
the TSOFIn, TSERn, and TSOFOn / TDENn signals but can also be used as the
reference for the TPOSn / TDATn and TNEGn signals.
This signal can be inverted.
o
DS3: 44.736 MHz +20 ppm
o
E3: 34.368 MHz +20 ppm
TGCLKn
: When the port is configured for framed DS3/E3 mode and TGCLKn is
selected, this gated output clock is enabled. This gapped clock is the same clock as
the internal framer transmit clock and is gated by TDENn. This clock is typically used
ROHSOFn
O
TCLKIn
I
TSOFIn
I
TSERn
I
TCLKOn /
TGCLKn
O