C8051F540DK
Rev. 0.1
11
7.4. Switches and LEDs (J11, J16)
Two push-button switches are provided on the target board for each MCU. Switch RESET_A is connected to the
RST pin of the C8051F540. Switch RESET_B is connected to the RST pin of the C8051F542. Pressing RESET_A
puts the C8051F540 device into its hardware-reset state, and similarly for RESET_B and the C8051F542 MCU.
Switches P1.4_A and P1.4_B are connected to the MCU’s general purpose I/O (GPIO) pins through headers.
Pressing either one of these switches generates a logic low signal on the port pin. Remove the shorting block from
the header to disconnect these switches from the port pins. See Table 1 for the port pins and headers
corresponding to each switch.
Four LEDs are provided on the target board to serve as indicators. The red LED labeled PWR indicates presence
of power to the target board. The second red LED labeled COMM indicates if the CP2102 USB-to-UART bridge is
recognized by the PC. The green LED on Side A is labeled with port pin name and is connected to a C8051F580
GPIO pin through a header. Remove the shorting block from the header to disconnect the LED from the port pin.
Similarly, a second green LED on Side B is connected to the C8051F542 through another header. See Table 1 for
the port pins and headers corresponding to each LED.
7.5. Target Board Debug Interfaces (P2 and P3)
The debug connectors P2 (DEBUG_A) and P3 (DEBUG_B) provide access to the debug (C2) pins of the
C8051F540 and C8051F542. The debug connectors are used to connect the Serial Adapter or the USB Debug
Adapter to the target board for in-circuit debugging and Flash programming. Table 2 shows the DEBUG pin
definitions.
Table 1. Target Board I/O Descriptions
Description
I/O
Header(s)
RESET_A
Reset (Side A)
none
RESET_B
Reset (Side B)
none
P1.4_A Switch
P1.4 (Side A)
J16[1–2]
P1.4_B Switch
P1.4 (Side B)
J11[1–2]
P1.3_A LED
P1.3 (Side A)
J16[3–4]
P1.3_B LED
P1.3 (Side B)
J11[3–4]
Red LED (PWR)
Power
none
Red LED (COMM)
COMM Active
none
Table 2. DEBUG Connector Pin Descriptions
Side A - C8051F540
Side B - C8051F542
Pin #
Description
Pin #
Description
1
Not Connected
1
Not Connected
2, 3, 9
GND (Ground)
2, 3, 9
GND (Ground)
4
P2.1_C2D_A
4
P2.1_C2D_B
5
RST_A (Reset)
5
RST_B (Reset)
6
P2.1
6
P2.1_B
7
RST/C2CK_A
7
RST/C2CK_B
8
Not Connected
8
Not Connected
10
USB Power (+5VDC from P2)
10
Not Connected
Summary of Contents for C8051F540DK
Page 17: ...C8051F540DK Rev 0 1 17 8 Schematics Figure 5 C8051F540 Target Board Schematic Page 1 of 4 ...
Page 18: ...C8051F540DK 18 Rev 0 1 Figure 6 C8051F540 Target Board Schematic Page 2 of 4 ...
Page 19: ...C8051F540DK Rev 0 1 19 Figure 7 C8051F540 Target Board Schematic Page 3 of 4 ...
Page 20: ...C8051F540DK 20 Rev 0 1 Figure 8 C8051F540 Target Board Schematic Page 4 of 4 ...
Page 21: ...C8051F540DK Rev 0 1 21 NOTES ...
