Philips Semiconductors
Preliminary specification
80C51 8-bit microcontroller
8K/256 OTP, 8 channel 10 bit A/D, I
2
C, PWM,
capture/compare, high I/O, low voltage (2.7V鈥?.5V), low power
P87C552
SPECIAL FUNCTION REGISTERS
S1ADR
S1DAT
S1STA
S1CON
CR2
ENS1
STA
ST0
SI
0
AA
0
CR!
GC
DB
DA
0
CR0
D9
D8
PSW
D0
IPO
PS1
B8
IEN0
EA
ES1
AB
P1
P1.7
P1.6
90
80
INTERNAL DATA RAM
7F
BACKUP
NUMBYTMST
SLA
HADD
ORIGINAL VALUE OF NUMBYTMST
NUMBER OF BYTES AS MASTER
SLA+R/W TO BE TRANSMITTED TO SLA
HIGHER ADDRESS BYTE INTERRUPT ROUTINE
SLAVE TRANSMITTER DATA RAM
53
52
51
50
4F
STD
SLAVE RECEIVER DATA RAM
SRD
MASTER RECEIVER DATA RAM
MRD
MASTER TRANSMITTER DATA RAM
MTD
48
40
38
30
R1
R0
19
18
00
SU00978
Figure 46. SIO1 Data Memory Map
1999 Mar 30
50