
DS26528 Octal T1/E1/J1 Transceiver
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NAME
PIN
TYPE
FUNCTION
TCHBLK/
CLK1
A5
TCHBLK/
CLK2
C7
TCHBLK/
CLK3
L7
TCHBLK/
CLK4
P7
TCHBLK/
CLK5
P9
TCHBLK/
CLK6
P11
TCHBLK/
CLK7
D10
TCHBLK/
CLK8
E11
O
Transmit Channel Block/Transmit Channel Block Clock. A dual function pin.
TCHBLK is a user-programmable output that can be forced high or low during any
of the channels. It is synchronous with TCLK when the transmit-side elastic store is
disabled. It is synchronous with TSYSCLK when the transmit-side elastic store is
enabled. It is useful for blocking clocks to a serial UART or LAPD controller in
applications where not all channels are used such as Fractional T1, Fractional E1,
384kbps (H0), 768kbps, or ISDN-PRI. Also useful for locating individual channels
in drop-and-insert applications, for external per-channel loopback, and for per-
channel conditioning.
TCHCLK. TCHCLKn is a dual function pin that can output either a gapped clock or
a channel clock. In gapped clock mode, TCHCLKn is a N x 64kHz fractional clock
that is software programmable for 0 to 24 channels and the F-bit (T1) or 0 to 32
channels (E1). In channel clock mode, TCHCLKn is a 192kHz (T1) or 256kHz (E1)
clock that pulses high during the LSB of each channel. It is useful for parallel-to-
serial conversion of channel data. In either mode, TCHCLKn is synchronous with
TCLKn when the receive-side elastic store is disabled or it is synchronous with
TSYSCLKn when the receive-side elastic store is enabled. The mode of TCHCLK
is determined by the TGCLKEN bit in the TESCR register.
RECEIVE FRAMER
RSER1
E5
RSER2
D6
RSER3
N4
RSER4
N6
RSER5
M11
RSER6
M12
RSER7
B12
RSER8
F11
O
Received Serial Data. Received NRZ serial data. Updated on rising edges of
RCLK when the receive-side elastic store is disabled. Updated on the rising edges
of RSYSCLK when the receive-side elastic store is enabled.
When IBO mode is used, the RSER pins can output data for multiple framers. The
RSER data is synchronous to RSYSCLK. This is described in Section
8.8.2.
RCLK1
F4
RCLK2
G4
RCLK3
L4
RCLK4
M4
RCLK5
K13
RCLK6
J13
RCLK7
F13
RCLK8
E13
O
Receive Clock. A 1.544MHz (T1) or 2.048MHz (E1) clock that is used to clock
data through the receive-side framer. This clock is recovered from the signal at
RTIP and RRING. RSER data is output on the rising edge of RCLK. RCLK is used
to output RSER when the elastic store is not enabled or IBO is not used. When the
elastic store is enabled or IBO is used, the RSER is clocked by RSYSCLK.
RSYSCLK
L12
I
Receive System Clock. 1.544MHz, 2.048MHz, 4.096MHz, 8.192MHz, or
16.384MHz receive backplane clock. Only used when the receive-side elastic store
function is enabled. Should be tied low in applications that do not use the receive-
side elastic store. Multiple of 2.048MHz is expected when the IBO mode is used.
Note that RSYSCLK is used for all eight transceivers.
RSYNC1
A4
RSYNC2
B6
RSYNC3
N5
RSYNC4
T6
RSYNC5
R10
RSYNC6
P12
RSYNC7
C11
RSYNC8
D13
I/O
Receive Synchronization. If the receive-side elastic store is enabled, then this
signal is used to input a frame or multiframe boundary pulse. If set to output frame
boundaries, then RSYNC can be programmed to output double-wide pulses on
signaling frames in T1 mode. In E1 mode, RSYNC out can be used to indicate
CAS and CRC-4 multiframe. The DS26528 can accept H.100-compatible
synchronization signal. The default direction of this pin at power-up is input, as
determined by the RSIO control bit in the
RIOCR.2 register.