C 8 0 5 1 F 3 2 x
8
Rev. 0.9
4.3. Universal Serial Bus (USB) Interface (J14)
A Universal Serial Bus (USB) connector (J14) is provided to facilitate connections to the USB interface on the
C8051F320. Table 2 shows the J14 pin definitions.
4.4. Expansion I/O Connector (J1)
The 32-pin Expansion I/O connector J1 provides access to all signal pins of the C8051F320 device. Pins for +3 V,
digital ground and the output of an on-board low-pass filter are also available. A small through-hole prototyping
area is also provided. All I/O signals routed to connector J1 are also routed to through-hole connection points
between J1 and the prototyping area (see Figure 4 on page 6). Each connection point is labeled indicating the
signal available at the connection point. See Table 3 for a list of pin descriptions for J1.
4.5. USB Self-Powered Configuration (J2, J11)
The C8051F320 target board can be configured as a self-powered USB device to take power from the USB cable
instead of the ac/dc adapter connected at P1. To configure the target boards as a self-powered USB device,
remove the shorting block from J2 and install on J11. (A shorting block should only be installed on J2 or J11, never
both at the same time.) Install shorting blocks in the following manner:
J2(ON) & J11(OFF)
Target Board is powered from the ac/dc Adapter at P1.
J2(OFF) & J11(ON)
Target Board is powered from the USB connection
Note:
When the C8051F320 target board is self-powered from the USB, the Serial Adapter is not powered from the
target board. The Serial Adapter must be powered directly by connecting the ac/dc adapter to the Serial Adapters’
dc power jack. Also, the RS232 Serial Interface (J5) cannot be used when powering the target board from the USB.
Table 2. USB Connector Pin Descriptions
Pin #
Description
1
VBUS
2
D-
3
D+
4
GND (Ground)
Table 3. J1 Pin Descriptions
Pin #
Description
Pin #
Description
Pin #
Description
1
+3 VD (+3.3 VDC)
13
P1.2
25
P2.6
2
PWM Output
14
P1.3
26
P2.7
3
P0.0
15
P1.4
27
P3.0
4
P0.1
16
P1.5
28
/RST (Reset)
5
P0.2
17
P1.6
29
VREGIN
6
P0.3
18
P1.7
30
VDD
7
P0.4
19
P2.0
31
VBUS
8
P0.5
20
P2.1
32
GND (Ground)
9
P0.6
21
P2.2
10
P0.7
22
P2.3
11
P1.0
23
P2.4
12
P1.1
24
P2.5
