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
Table 7.
Master Receiver Mode
APPLICATION SOFTWARE RESPONSE
TO S1CON
2
STATUS
CODE
(S1STA)
STATUS OF THE I C
BUS AND
NEXT ACTION TAKEN BY SIO1 HARDWARE
TO/FROM S1DAT
SIO1 HARDWARE
STA STO
SI
AA
08H
10H
A START condition has
been transmitted
Load SLA+R
X
0
0
X
SLA+R will be transmitted;
ACK bit will be received
Load SLA+R or
Load SLA+W
X
X
0
0
0
0
X
X
As above
SLA+W will be transmitted;
SIO1 will be switched to MST/TRX mode
A repeated START
condition has been
transmitted
2
No S1DAT action or
No S1DAT action
0
1
0
0
0
0
X
X
I C bus will be released;
38H
40H
48H
Arbitration lost in
NOT ACK bit
SIO1 will enter a slave mode
A START condition will be transmitted when the
bus becomes free
No S1DAT action or
no S1DAT action
0
0
0
0
0
0
0
1
Data byte will be received;
NOT ACK bit will be returned
Data byte will be received;
ACK bit will be returned
SLA+R has been
transmitted; ACK has
been received
No S1DAT action or
no S1DAT action or
1
0
0
1
0
0
X
X
Repeated START condition will be transmitted
STOP condition will be transmitted;
STO flag will be reset
SLA+R has been
transmitted; NOT ACK
has been received
no S1DAT action
1
1
0
X
STOP condition followed by a
START condition will be transmitted;
STO flag will be reset
Read data byte or
read data byte
0
0
0
0
0
0
0
1
Data byte will be received;
NOT ACK bit will be returned
Data byte will be received;
ACK bit will be returned
50H
58H
Data byte has been
received; ACK has been
returned
Read data byte or
read data byte or
1
0
0
1
0
0
X
X
Repeated START condition will be transmitted
STOP condition will be transmitted;
STO flag will be reset
Data byte has been
received; NOT ACK has
been returned
read data byte
1
1
0
X
STOP condition followed by a
START condition will be transmitted;
STO flag will be reset
44
1999 Mar 30
NXP [ NXP ]
