2001 Apr 06

9

Philips Semiconductors

Preliminary specification

P87C51MB2/P87C51MC2

80C51 8-bit microcontroller family with extended memory

64KB/96KB OTP with 2KB/3KB RAM

SPECIAL FUNCTION REGISTERS

Note: Special Function Register (SFR) accesses are restricted in the following ways:

1. User must NOT attempt to access any SFR locations not defined.

2. SFR bits labeled ’-’, ’0’ or ’1’ can ONLY be written and read as follows:

- ’-’ MUST be written with ’0’, but can return any value when read (even if it was written with ’0’). It is a reserved bit and may

be used in future derivatives.

- ’0’ MUST be written with ’0’, and will return a ’0’ when read.

- ’1’ MUST be written with ’1’, and will return a ’1’ when read.

Special Function Registers

SYMBOL

DESCRIPTION

DIRECT

ADDRESS

BIT ADDRESS, SYMBOL, OR ALTERNATE PORT FUNCTION

Reset

Value

MSB

LSB

E7

E6

E5

E4

E3

E2

E1

E0

ACC*

Accumulator

E0H

00H

AUXR#

Auxiliary Function Register

8EH

-

-

-

-

-

-

EXTRAM

AO

AUXR1#

Auxiliary Function Register 1

A2H

-

-

-

LPEP

GF2

0

-

DPS

F7

F6

F5

F4

F3

F2

F1

F0

B*

B Register

F0H

00H

BRGR0#§

Baud Rate Generator Rate Low

BRATE11 BRATE10

BRATE9

BRATE8

BRATE7

BRATE6

BRATE5

BRATE4

00H

BRGR1#§

Baud Rate Generator Rate High

BRATE3

BRATE2

BRATE1

BRATE0

-

-

-

-

BRGCON# Baud Rate Generator Control

-

-

-

-

-

-

S0BRGS

BRGEN

CCAP0H#

Module 0 Capture High

FAH

XXH

CCAP1H#

Module 1 Capture High

FBH

XXH

CCAP2H#

Module 2 Capture High

FCH

XXH

CCAP3H#

Module 3 Capture High

FDH

XXH

CCAP4H#

Module 4 Capture High

FEH

XXH

CCAP0L#

Module 0 Capture Low

EAH

XXH

CCAP1L#

Module 1 Capture Low

EBH

XXH

CCAP2L#

Module 2 Capture Low

ECH

XXH

CCAP3L#

Module 3 Capture Low

EDH

XXH

CCAP4L#

Module 4 Capture Low

EEH

XXH

CCAPM0#

Module 0 Mode

DAH

-

ECOM_0

CAPP_0

CAPN_0

MAT_0

TOG_0

PWM_0

ECCF_0

CCAPM1#

Module 1 Mode

DBH

-

ECOM_1

CAPP_1

CAPN_1

MAT_1

TOG_1

PWM_1

ECCF_1

CCAPM2#

Module 2 Mode

DCH

-

ECOM_2

CAPP_2

CAPN_2

MAT_2

TOG_2

PWM_2

ECCF_2

CCAPM3#

Module 3 Mode

DDH

-

ECOM_3

CAPP_3

CAPN_3

MAT_3

TOG_3

PWM_3

ECCF_3

CCAPM4#

Module 4 Mode

DEH

-

ECOM_4

CAPP_4

CAPN_4

MAT_4

TOG_4

PWM_4

ECCF_4