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e. Message format either on menu screens or in the TL1/ITL1 language.
f. Remote port which can be configured manually as an Ethernet port.
g. On-card switch for setting the baud rate (not currently used).
5.112 Circuit
Description
The 54550 block diagram appears in Figure 5-10.
5.1121 General
The 54550 receives alarm signals from every other card on the shelf and
processes these to report status. It uses serial data interfaces to
communicate with the track and hold and 54541/54542 Synchronization
Monitor Card(s) and the one-wire interface to communicate with these and all
the other cards. The communication interfaces are bidirectional. The 54550
receives switch settings, LED status, alarm status, and personality information
from the other cards and transmits configuration information to them.
5.1122 Microprocessor
The microprocessor, data latch, address latch, address decoder, RAM, and
ROM perform all the controlling and communication functions of this card. The
54550 card uses the MC68332 which is a highly integrated 32-bit
microcontroller (MCU), combining high performance data manipulation
capabilities with powerful peripheral subsystems. The MCU is built up from
standard modules that interface through a common intermodule bus (IMB).
The MCU incorporates a 32-bit central processing unit (CPU32), a system
integration module (SIM), a time processor unit (TPU), a queued serial module
(QSM), and a 2-kbyte static RAM module with TPU emulation capability
(TPURAM).
5.1123 Chip
Selects
The microcontroller includes 12 programmable chip-select circuits that can
provide 2- to 20-clock cycle access to external memory and peripherals.
Address block sizes of two kbytes to one Mbyte can be selected.
5.1124 Dual
UART
The serial ports of the 54541/54542 Synchronization Monitor Cards are
connected to an XR68C681 Dual UART (Universal Asynchronous
Receiver/Transmitter) on the 54550. Channel 1 is connected to SMC A and
Channel 2 to SMC B.
5.1125 Quad
UART
The 54550 also contains a four-channel UART. Two channels of the Quad
UART provide serial data links to the A and B clock cards for status reporting
and clock mode control. The other two channels are connected to the local
and remote ports. These provide communication via a local or remote
terminal.
