Personal Computer User Manual

Functional Description
MVME197LEIG/D1 1-7
1
Functional Description
The following sections contain a functional description of the major blocks on
the MVME197LE single board computer.
Front Panel Switches and Indicators
There are two push-button switches and six LEDs on the front panel of the
MVME197LE module. The switches are RESET and ABORT. The RESET
switch (S3) will reset all onboard devices and drive the SYSRESET* signal if the
board is the system controller. The RESET switch (S3) will reset all onboard
devices except the DCAM and ECDM if the board is not the system controller.
The VMEchip2 generates the SYSREST* signal. The BusSwitch combines the
local reset and the reset switch to generate a local board reset. Refer to the Reset
Driver section in the VMEchip2 chapter of the MVME197LE, MVME197DP, and
MVME197SP Single Board Computers Programmer’s Reference Guide for more
information.
When enabled by software, the ABORT switch (S2) generates an interrupt at a
user-programmable level. It is normally used to abort program execution and
return to the debugger. Refer to the VMEchip2 chapter of the MVME197LE,
MVME197DP, and MVME197SP Single Board Computers Programmer’s Reference
Guide for more information.
The six LEDs on the MVME197LE front panel are: FAIL, SCON, RUN, LAN,
VME, and SCSI.
1. The yellow FAIL LED (DS1) is lit when the BRDFAIL signal line is active.
2. The green SCON LED (DS2) is lit when the VMEchip2 is the VMEbus
system controller.
3. The green RUN LED (DS3) is lit when the MC88110 bus MC* pin is low.
4. The green LAN LED (DS4) lights when the LAN chip is the local
peripheral bus master.
5. The green VME LED (DS5) lights when the board is using the VMEbus or
when the board is accessed by the VMEbus.
6. The green SCSI LED (DS6) lights when the SCSI chip is the local peripheral
bus master.