Toshiba Strata AirLink Installation Manual page 69

The WWIS PCB (see
o Four E1 transceivers with crystals, line transformers, protectors, and electronic circuit
breakers
o Two LEDS for each transceiver
o Eight elastic buffers, two for each E1 interface
o Surface Mount Technology (SMT) resistors and capacitors
WWIS (side view)
Figure 29 Top and Side View of WWIS
The thickness of the RWIU is 1.6 mm and the maximum distance between the WWIS PCB
(including the height of the mounted components) is 30 mm.
Signaling
A high density Mach decoder generates all the chip select signals and control signals for Erasable
Programmable Read Only Memory (EPROM), flash and RAM memories, peripherals, and Input/
Output (I/O) devices. The Mach device includes a serial interface on connector J7 for on-board
programming.
The digital I/O block has two digital input buffers and four output D flip-flops for the digital
output signals. All input buffers and output flip-flops connect to the CPU lower data bus using a
bidirectional transceiver. All control signals are generated to the I/O devices by the Mach decoder.
A power ON external reset generator is provided by an internal WDT chip. There is also a power-
fail circuit that alerts the CPU when the voltage falls below 4.75V. This feature is necessary
because the CPU stores data in the backup memory of the RTC during a power failure.
An RTC chip mounts on the RWIU PCB only. It has an internal Lithium battery and an internal
backup 2KB of SRAM memory, powered by the same Lithium battery.
The RWIU interfaces to the Strata DK system using a 32 time slot, 2.048 MHz Pulse Code
Modulator (PCM) channel. The PCM channel has the following signals:
o PHOUT – 32 time slots (receiving data)
o PHIN – 32 time slots (transmitting data)
o PHFS – 8 KHz frame synchronization output
Strata AirLink Installation Guide
Figure 29) has the following components:
WWIS1A
TOSHIBA
WWIS (top view)
P9
J1 J2
LED1
J1 J2
LED`
5/00
P16 P17
P14 P15
P13
P10
P12
J3 J4
LED2 LED3 LED4
J3 J4
LED2 LED3 LED4
RWIU System Installation
RWIU Additional Information
59