SC65D02P40

3.3 P3 port

[Description]

P3 of SC65D02P40 has only one bit which is only as output port.

3.4 ROM

[Description]

SC65D02P40 has built-in 8K-byte read-only memory(ROM), and the address range is 6000H ~ 7FFFH. This

ROM is masked with code transmitting program which can simplify the main program development of the

customer circuit and self-test program, etc. Of course, the customer may not use the program in ROM.

3.5 OTP memory

[Description]

The address space of OTP memory is 8000H~FFFFH. OTP memory is mainly used to store the main program

and read-only data, where FFF0H~FFFFH is the configuration area including the reset vector and interrupt

vector in normal working mode and testing mode as well as the protect byte of the OTP, shown in figure 5:

Figure 5 – OTP configuration area

The reset vector value is the initial value of PC after the circuit is reset, that is the entry address of the main

program, where, the high byte is stored in FFFBH, and low byte is stored in FFFAH. For example: FFFAH

stores 40H, FFFBH stores 80H, then after the circuit is reset, then PC points to 8040H.

The interrupt vector value is the initial value of PC after MCU responses to the interrupt, which is the entry

address of the interrupt service routine, where, the high byte is stored in FFF9H, and low byte is stored in

FFF8H. For example: FFF8H stores 00H，FFF9H stores 80H, then the interrupt entry address is 8000H.

HANGZHOU SILAN MICROELECTRONICS CO.,LTD

REV:1.2

2008.07.21

Http: //www.silan.com.cn

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