Philips Semiconductors
Preliminary specification
80C51 8-bit microcontroller
8K/256 OTP, 8 channel 10 bit A/D, I2C, PWM,
capture/compare, high I/O, low voltage (2.7V–5.5V), low power
P87C552
!********************************************************************************************************
! INITIALIZATION ROUTINE
! Example to initialize IIC Interface as slave receiver or slave transmitter and
! start a MASTER TRANSMIT or a MASTER RECEIVE function. 4 bytes will be transmitted or received.
!********************************************************************************************************
.sect
strt
.base
0x00
0000
0200
4100
ajmp INIT
! RESET
.sect
.base
INIT:
initial
0x200
75DB31
mov S1ADR,#OWNSLA
! Load own SLA + enable
! general call recognition
! P1.6 High level.
0203
0205
0207
020A
020D
020F
D296
D297
755001
43A8A0
C2BD
setb P1(6)
setb P1(7)
mov HADD,#PAG1
! P1.7 High level.
orl
clr
IEN0,#ENSI01
SI01HP
! Enable SI01 interrupt
! SI01 interrupt low priority
75D8C5
mov S1CON, #ENS1_NOTSTA_NOTSTO_NOTSI_AA_CR0
! Initialize SLV funct.
!********************************************************************************************************
!– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
! START MASTER TRANSMIT FUNCTION
!– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
0212
0215
0218
755204
7551C0
D2DD
mov NUMBYTMST,#0x4
mov SLA,#SLAW
setb STA
! Transmit 4 bytes.
! SLA+W, Transmit funct.
! set STA in S1CON
!– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
! START MASTER RECEIVE FUNCTION
!– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
021A
021D
0220
755204
7551C1
D2DD
mov NUMBYTMST,#0x4
mov SLA,#SLAR
setb STA
! Receive 4 bytes.
! SLA+R, Receive funct.
! set STA in S1CON
!********************************************************************************************************
! SI01 INTERRUPT ROUTINE
!********************************************************************************************************
.sect
.base
intvec
0x00
! SI01 interrupt vector
! S1STA and HADD are pushed onto the stack.
! They serve as return address for the RET instruction.
! The RET instruction sets the Program Counter to address HADD,
! S1STA and jumps to the right subroutine.
002B
002D
002F
0031
C0D0
C0D9
C050
22
push psw
push S1STA
push HADD
ret
! save psw
! JMP to address HADD,S1STA.
!– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
! STATE : 00, Bus error.
! ACTION : Enter not addressed SLV mode and release bus. STO reset.
!– – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – – –
.sect
st0
.base
0x100
0100
75D8D5
mov S1CON,#ENS1_NOTSTA_STO_NOTSI_AA_CR0 ! clr SI
! set STO,AA
0103
0105
D0D0
32
pop psw
reti
53
1999 Mar 30
NXP [ NXP ]
