IDT82P2284
QUAD T1/E1/J1 LONG HAUL / SHORT HAUL TRANSCEIVER
Pin Description
17
February 25, 2008
Clock Generator
OSCI
Input
B13
OSCI: Crystal Oscillator Input
This pin is connected to an external clock source. In T1 mode E1 Rate of Transmit System interface, this
clock must keep the source same with system transmit clock (TSCKn/MTSCK).
The clock frequency of OSCI is defined by CLK_SEL[2:0]. The clock accuracy should be ±32 ppm and duty
cycle should be from 40% to 60%.
OSCO
Output
C13
OSCO: Crystal Oscillator Output
This pin outputs the inverted, buffered clock input from OSCI.
CLK_SEL[0]
CLK_SEL[1]
CLK_SEL[2]
Input
D15
C14
B15
CLK_SEL[2:0]: Clock Selection
These three pins select the input clock signal:
When the CLK_SEL[2] pin is low, the input clock signal is N X 1.544 MHz;
When the CLK_SEL[2] pin is high, the input clock signal is N X 2.048 MHz.
When the CLK_SEL[1:0] pins are ‘00’, the N is 1;
When the CLK_SEL[1:0] pins are ‘01’, the N is 2;
When the CLK_SEL[1:0] pins are ‘10’, the N is 3;
When the CLK_SEL[1:0] pins are ‘11’, the N is 4.
CLK_SEL[2:0] are Schmitt-trigger inputs.
CLK_GEN_1.544
Output
A16
CLK_GEN_1.544: Clock Generator 1.544 MHz Output
This pin outputs the 1.544 MHz clock signal generated by the Clock Generator.
CLK_GEN_2.048
Output
D14
CLK_GEN_2.048: Clock Generator 2.048 MHz Output
This pin outputs the 2.048 MHz clock signal generated by the Clock Generator.
REFA_OUT
Output
A15
REFA_OUT: Reference Clock Output A
The frequecy is 2.048 MHz (E1) or 1.544 MHz (T1/J1)
When no LOS is detected, this pin outputs a recovered clock from the Clock and Data Recovery function
block of one of the four links. The link is selected by the RO1[1:0] bits (b1~0, T1/J1-007H / b1~0, E1-007H).
When LOS is detected, this pin outputs MCLK or high level, as selected by the REFH_LOS bit (b0, T1/J1-
03EH,... / b0, E1-03EH,...). *
Note: MCLK is a clock derived from OSCI using an internal PLL, and the frequency is 2.048 MHz(E1) or 1.544
MHz(T1/J1).
REFB_OUT
Output
B14
REFB_OUT: Reference Clock Output B
The frequecy is 2.048 MHz(E1) or 1.544 MHz(T1/J1).
When no LOS is detected, this pin outputs a recovered clock from the Clock and Data Recovery function
block of one of the four links. The link is selected by the RO2[1:0] bits (b4~3, T1/J1-007H / b4~3, E1-007H).
When LOS is detected, this pin outputs MCLK or high level, as selected by the REFH_LOS bit (b0, T1/J1-
03EH,... / b0, E1-03EH,...). *
Control Interface
RESET
Input
A14
RESET: Reset (Active Low)
A low pulse for more than 100 ns on this pin resets the device. All the registers are accessible 2 ms after the
reset. The RESET pin is a Schmitt-trigger input with a weak pull-up resistor. The OSCI clock must exist when
the device be reset.
GPIO[0]
GPIO[1]
Output / Input
E13
D13
General Purpose I/O [1:0]
These two pins can be defined as input pins or output pins by the DIR[1:0] bits (b1~0, T1/J1-006H / b1~0, E1-
006H) respectively. When the pins are input, their polarities are indicated by the LEVEL[1:0] bits (b3~2, T1/J1-
006H / b3~2, E1-006H) respectively. When the pins are output, their polarities are controlled by the
LEVEL[1:0] bits (b3~2, T1/J1-006H / b3~2, E1-006H) respectively.
GPIO[1:0] are Schmitt-trigger input/output with a pull-up resistor.
THZ
Input
B16
THZ: Transmit High-Z
A high level on this pin puts all the TTIPn/TRINGn pins into high impedance state.
THZ is a Schmitt-trigger input.
Name
Type
Pin No.
Description
Note:
* This feature is available in ZB revision only.