UPSD3354DV-40U6 Datasheet, PDF (130/272 Pages) STMicroelectronics – fast 8032 MCU with programmable logic

I²C interface
UPSD33xx
Table 74.
Bit 7
GC
S1STA: I²C Interface Status register (SFR DDh, reset value 00h)
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
STOP
INTR TX_MODE BBUSY BLOST ACK_RESP SLV
Table 75. S1STA register bit definition
Bit Symbol R/W
Function
General Call flag
GC = 1 if the General Call address of 00h was received when SIOE is in
7
GC
R Slave mode, and GC is cleared by a START or STOP condition on the
bus. If the SIOE is in Master mode when GC = 1, the Bus Lost condition
exists, and BLOST = 1.
STOP flag
6
STOP
R _{STOP = 1 while SIOE detects a STOP condition on the bus when in}
Master or Slave mode.
Interrupt flag
) 5
INTR R,W _{INTR is set to 1 by any of the five I}²_{C interrupt conditions listed above.}
t(s ^{INTR must be cleared by firmware.}
c _{Transmission Mode flag}
u _{4 TX_MODE R TX_MODE = 1 whenever the SIOE is in Master-Transmitter or Slave-}
d _{Transmitter mode. TX_MODE = 0 when SIOE is in any receiver mode.}
ro _{Bus Busy flag}
te ^{P 3}
BBUSY
R ^{BBUSY = 1 when the I2C bus is in use. BBUSY is set by the SIOE when}
a START condition exists on the bus and BBUSY is cleared by a STOP
le condition.
so ^{Bus Lost flag}
b 2
BLOST R _{BLOST is set when the SIOE is in Master mode and it looses the}
O ^{arbitration process to another Master device on the bus.}
- _{Not Acknowledge Response flag}
t(s) ^{While SIOE is in Transmitter mode:}
– After SIOE sends a byte, ACK_RESP = 1 whenever the external I²C
c _{device receives the byte, but that device does NOT assert an}
u _{accolade signal (external device asserted a high on SDA during the}
d _{acknowledge bit-time).}
ro _{1 ACK_RESP R – After SIOE sends a byte, ACK_RESP = 0 whenever the external I}2_C
P _{device receives the byte, and that device DOES assert an accolade}
te ^{signal (external device drove a low on SDA during the acknowledge}
bit-time)
le _{Note: If SIOE is in Master-Transmitter mode, and ACK_RESP = 1 due to}
so ^{a Slave-Transmitter not sending an Acknowledge, a STOP condition will}
b not automatically be generated by the SIOE. The STOP condition must
O ^{be generated with S1CON.STO = 1.}
Slave Mode flag
0
SLV
R SLV = 1 when the SIOE is in Slave mode. SLV = 0 when the SIOE is in
Master mode (default).
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Doc ID 9685 Rev 7