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Cpu base clock select (jp1) -4, Switch settings (sw1) -4, External led header (j1) -4 – Acrosser AR-B1320 User Manual

Page 23: 2 cpu base clock select (jp1), 3 switch settings (sw1), 4 external led header (j1)

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A

A

R

R

-

-

B

B

1

1

3

3

2

2

0

0

U

U

s

s

e

e

r

r

s

s

G

G

u

u

i

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d

e

e


3-4

3.2

CPU BASE CLOCK SELECT (JP1)

This board provides six types of CPU input clocks; they are 33.3MHz, 50MHz, 60MHz, 66.7MHz,
75MHz, and 80MHz. The CPU input clock is twice that of the operating clock. JP1 is a 6-pin
jumper located between CN3 and CN4.

CPU Input Clock

CPU Operating Clock

JP1 Setting

Remark

33.3MHz

16.7MHz

Short 1-2 & 4-6

50MHz

25MHz

Short 1-2 & 3-5

60MHz

30MHz

Short 1-2 & 5-6

66.7MHz

33.3MHz

Short 1-3 & 5-6

Factory Preset

75MHz

37.5MHz

Short 2-4 & 5-6

80MHz

40MHz

Short 1-3 & 2-4

Table 3-2 CPU Clock Settings

Figure 3-2 JP1: CPU Clock Select

3.3

SWITCH SETTINGS (SW1)

SW1 is a 6-SPST DIP switch. It provides multi-purpose selection in one switch. The following
table gives the details:

SW1

Function

When “OFF”

When “ON”

Factory Preset

Switch 1

Selects the base I/O address of SSD

210H-211H

290H-291H

Off

Switch 2

Selects the memory segment of SSD

C800H(8KB)

D800H(8KB)

Off

Switch 2 Selects the memory segment of DiskOnChip

(If Switch 3 is set as “ON”)

CA00H(8KB) DA00H(8KB)

Off

Switch 3

DiskOnChip select

Disabled

Enabled

Off

Switch 4

Reserved

---

---

Off

Switch 5

COM-A port mode select

RS-232C

RS-485

Off

Switch 6

COM-B port mode select

RS-232C

RS-485

Off

Table 3-3 SW1 Settings

3.4

EXTERNAL LED HEADER (J1)

The J1 is a 4-pin right angle header. It allows you to connect an external power LED and an
external hard disk LED.

Figure 3-3 J1: External LED Header

1

3

5

6

4

2

JP1

16.7MHz

1

3

5

6

4

2

JP1

25MHz

1

3

5

6

4

2

JP1

30MHz

1

3

5

6

4

2

JP1

33.3MHz

1

3

5

6

4

2

JP1

37.5MHz

1

3

5

6

4

2

JP1

40MHz

2

1

3

4

J1

Front View

1: Power LED+
3: Power LED-
2: Hard Disk LED+
4: Hard Disk LED-