AT89C51RE2 Atmel Corporation, AT89C51RE2 Datasheet - Page 138

• Manufacturer Part Number: AT89C51RE2
• Manufacturer: Atmel Corporation

Specifications of AT89C51RE2

• Flash (kbytes): 128 Kbytes
• Max. Operating Frequency: 60 MHz
• Cpu: 8051-12C
• Max I/o Pins: 34
• Spi: 1
• Uart: 2
• Sram (kbytes): 8.25
• Self Program Memory: API
• Operating Voltage (vcc): 2.7 to 5.5
• Timers: 4
• Isp: UART/OCD
• Watchdog: Yes

Table 102. Status in Master Transmitter Mode
138
SSSTA
Status
Code
08h
10h
18h
20h
28h
30h
38h
Status of the Two-
wire Bus and Two-
wire Hardware
A START condition has
been transmitted
A repeated START
condition has been
transmitted
SLA+W has been
transmitted; ACK has
been received
SLA+W has been
transmitted; NOT ACK
has been received
Data byte has been
transmitted; ACK has
been received
Data byte has been
transmitted; NOT ACK
has been received
Arbitration lost in
SLA+W or data bytes
AT89C51RE2
To/From SSDAT
Write SLA+W
Write SLA+W
Write SLA+R
Write data byte
No SSDAT action
No SSDAT action
No SSDAT action
Write data byte
No SSDAT action
No SSDAT action
No SSDAT action
Write data byte
No SSDAT action
No SSDAT action
No SSDAT action
Write data byte
No SSDAT action
No SSDAT action
No SSDAT action
No SSDAT action
No SSDAT action
Application software response
SSSTA
X
X
X
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
SSSTO
To SSCON
0
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
SSI
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
SSAA
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Next Action Taken by Two-wire Hardware
SLA+W will be transmitted.
SLA+W will be transmitted.
SLA+R will be transmitted.
Logic will switch to master receiver mode
Data byte will be transmitted.
Repeated START will be transmitted.
STOP condition will be transmitted and SSSTO flag
will be reset.
STOP condition followed by a START condition will
be transmitted and SSSTO flag will be reset.
Data byte will be transmitted.
Repeated START will be transmitted.
STOP condition will be transmitted and SSSTO flag
will be reset.
STOP condition followed by a START condition will
be transmitted and SSSTO flag will be reset.
Data byte will be transmitted.
Repeated START will be transmitted.
STOP condition will be transmitted and SSSTO flag
will be reset.
STOP condition followed by a START condition will
be transmitted and SSSTO flag will be reset.
Data byte will be transmitted.
Repeated START will be transmitted.
STOP condition will be transmitted and SSSTO flag
will be reset.
STOP condition followed by a START condition will
be transmitted and SSSTO flag will be reset.
Two-wire bus will be released and not addressed
slave mode will be entered.
A START condition will be transmitted when the bus
becomes free.
7663D–8051–10/08