RTE-V821-PC
USER’ S MANUAL
6
3. BOARD CONFIGURATION
The physical layout of the major components on the RTE-V821-PC board is shown below. This
chapter explains each component.
RTE-V821-PC Board Top View
3.1. RESET SWITCH (SWRESET)
SWRESET is a reset switch. Pressing this switch causes the CPU to be reset.
3.2. POWER SUPPLY CONNECTOR (JPOWER)
When this board is to be used as a standalone, that is, without being inserted in an ISA bus slot,
the board should be supplied with power from an external power supply by connecting it to the
JPOWER connector.
The external power should be one rated as listed below.
Voltage: 5 V
Current: Maximum of 1 A (excluding the current supplied to the JEXT connector)
Mating connector: Type A (5.5 mm in diameter)
Polarity:
GND
GND
+5V
+5V
[Caution]
When attaching an external power supply to the board, be careful about its
connector polarity. When inserting the board into the ISA bus slot, do not attach the JPOWER
connector to an external power supply.
3.3. SWITCH1 (SW1)
SW1 is a switch for selecting the I/O address of the ISA bus. Switch contacts 1 to 8
corresponds to ISA addresses A4 to A11, respectively (A12 to A15 are fixed at 0). This means
that the I/O address that can be selected ranges between 000xH and 0FFxH. When a switch
contact is open, it corresponds to 1. When it is closed, it corresponds to 0.
SW1
contact
1
2
3
4
5
6
7
8
Address
A4
A5
A6
A7
A8
A9
A10
A11
SW1-to-ISA Address Correspondence
SW2
POWER
CS0
CS1
CS2
CS3
TOVER
P06
P07
SCC/
TIMER
LED
TP
DRAM SIMM
JCPU
SWRESET
JPOWER
JEXT
V821
JSIO
JSUBPORT
SRAM
SW1
ROM
PLD
PLD
NMI-
RD_WRALL-
RESET-
GND
PIO
OSC1
