AR-B1375/AR-B1376 User s Guide
3-10
(2) External Battery Connector (J11)
J11 allows users to connector an external 4.5 to 6 VDC battery to the AR-B1375 and AR-B1376 if the on-board
battery is fully discharged. The SRAM disk will draw the battery current. The battery charger on AR-B1375 and
AR-B1376 doesn’t source charge current to the external battery, which connects to J11.
12
1 Battery+
2 Battery-
Figure 3-23 J11: External Battery Connector
3.2.12 CPU Base Clock Select (JP1)
The CPU base clock (Input clock) is twice of its operation clock.
1
2
3
4
50MHz
Factory Preset
1
2
3
4
80MHz
1
2
3
4
66.67MHz
Figure 3-24 JP1: CPU Base Clock Select
3.2.13 DRAM Configuration
There is two 32-bit memory banks on the AR-B1375/AR-B1376 board. It can only put one-side DRAM SIMM to
SIMM Socket (Single-Line Memory Modules), which is designed to accommodate 256KX36 bit to 4MX36-SIMMs.
This provides the user with up to 32MB of main memory. The 32-bit SIMM (without parity bit) also can be used on
AR-B1375/AR-B1376 board. There are six on-board memory configurations available. Please refer to the
following table for details:
SIMM1 SIMM2 Total Memory
256KX32 (X36) None 1MB
256KX32 (X36) 256KX32 (X36) 2MB
256KX32 (X36) 1MX32 (X36) 5MB
256KX32 (X36) 4MX32 (X36) 17MB
1MX32 (X36) None 4MB
1MX32 (X36) 256KX32 (X36) 5MB
1MX32 (X36) 1MX32 (X36) 8MB
1MX32 (X36) 4MX32 (X36) 20MB
4MX32 (X36) None 16MB
4MX32 (X36) 256KX32 (X36) 17MB
4MX32 (X36) 1MX32 (X36) 20MB
4MX32 (X36) 4MX32 (X36) 32MB
Table 3-3 DRAM Configuration