Location and Function of Parts
CPU-252
Front
1 Connector CN5
2 Switch S3
3 Switch S1
4 Connector CN3
5 Indicator D2
6 Test pin TP2
7 Test pins TP4 and TP5
8 Test pin TP3
9 Test pin TP1
0 Indicator D4
!¡ Indicator D3
!™ Test pin TP8
!£ Test pin TP6
!¢ Test pin TP7
1 Connector CN5 (9-pin, RS-232C, female)
Used to load firmware on the flash ROM.
2 Switch S3
Resets the processor.
3 Switch S1
Abort switch, used in firmware development.
4 Connector CN3 (16-pin, parallel I/O)
Used to load firmware on the flash ROM for
debugging.
5 Indicator D2
Lights when the processor stops due to some
malfunction.
6 Test pin TP2
Used to check the processor clock signal.
2(E)
B
C
A
1
2
3
4
7 Test pin TP4, TP5
Used to check the processor timer output.
8 Test pin TP3
Used to check the input reference signal.
9 Test pin TP1
Used to check the signal to reset the processor. The
output level of this pin will be low when Switch S32
is pressed or the PC is powered up.
0 Indicator D4
Lights when the processor stops due to some
malfunction.
!¡ Indicator D3
Lights when the processor receives a reset signal.
!™ Test pin TP8
Unused (reserved for checking the processor I/O port
outputs).
D
E
F