ROM-DB3900 User Manual
30
2.4.5
Switches and buttons
*default
10
SYSBUS_A18
SYSBUS_A19
SYSBUS_A26
SYSBUS_OE#
11
SYSBUS_A20
SYSBUS_A21
SYSBUS_WE#
GND
12
SYSBUS_A22
SYSBUS_A23
SYSBUS_A27
SYSBUS_A28
13
3.3V
SYSBUS_A29
SYSBUS_CS0#
SYSBUS_CS1#
14
SYSBUS_D0
SYSBUS_D1
SYSBUS_D15
SYSBUS_D14
15
SYSBUS_D2
SYSBUS_D3
SYSBUS_D13
SYSBUS_D12
16
SYSBUS_D4
SYSBUS_D5
SYSBUS_D11
SYSBUS_D10
17
SYSBUS_D6
SYSBUS_D7
SYSBUS_D9
SYSBUS_D8
18
N/C
N/C
N/C
N/C
19
N/C
N/C
N/C
N/C
20
N/C
N/C
N/C
N/C
21
N/C
N/C
N/C
N/C
22
N/C
N/C
SYSBUS_CLK
GND
23
N/C
N/C
N/C
GND
24
N/C
N/C
SYSBUS_BE1#
3.3V
25
N/C
N/C
N/C
3.3V
26
SYSBUS_BE0#
N/C
N/C
N/C
27
N/C
SYSBUS_ALE
5V
5V
28
N/C
N/C
SYSBUS_WAIT#
N/C
29
N/C
N/C
N/C
N/C
30
N/C
N/C
GND
N/C
Table 2.54: SYSTEM BUS
Table 2.55: SW2 (Boot selection)
1
2
3
Feature
ON
ON
ON
Carrier SATA
OFF
ON
ON
Carrier SD
ON
OFF
ON
Carrier eMMC
OFF
OFF
ON
Carrier SPI
ON
ON
OFF
Module device* (reserved)
OFF
ON
OFF
Remote boot (reserved)
ON
OFF
OFF
Module eMMC
OFF
OFF
OFF
Module SPI