Single chip microcomputer special function register

I/O port reading and writing as long as the data into the corresponding I/O port latch can be, then for the timing/ counter, serial I/O port how to use it? In the microcontroller, there are some independent storage units are used to control these devices, known as the Special Function register (SFR).

Symbol	Address	function Introduction
B	f0h	b Register
Acc	e0h	Accumulator
PSW	d0h	Program Status Word
Ip	b8h	Interrupt-Priority Control register
P3	b0h	P3 Port Latch
Ie	a8h	Interrupt Allow control register
P2	a0h	P2 Port Latch
Sbuf	99H	Serial Port latch
SCON	98H	Serial Port Control Register
P1	90H	P1 Port Latch
TH1	8DH	Timer/Counter 1 (High 8-bit)
TH0	8CH	Timer/Counter 1 (Low 8-bit)
TL1	8BH	Timer/Counter 0 (High 8-bit)
TL0	8AH	Timer/Counter 0 (Low 8-bit)
Tmod	89A	Timer/Counter Mode control register
TCON	88H	Timer/Counter Control register
DPH	83H	Data address pointer (8 bits high)
Dpl	82H	Data address pointer (low 8 bits)
Sp	81H	Stack pointer
P0	80H	P0 Port Latch
PCON	87H	Power Control Register

Table 1

Special function Register address image table

Common SFR:

1. Accumulator a 2. Register B 3. Program status word PSW 4.p0, P1, P2, P3

5.DPTR: A data pointer that can be used to access any unit of the external data memory, if not, can also be used as a general-purpose register, we have decided how to use. 16 bits, consisting of two 8-bit registers DPH, DPL. It is primarily used for storing a 16-bit address as an address pointer to external memory (outside RAM and ROM).

6.SP: Stack pointer. (specifically used to indicate the address of the top data on the stack.) ）

Using the stack this way to put data (a batch of time) only need to know the first Data address unit to be able to simplify the operation.

Single chip microcomputer special function register