UPSD3422_06 Datasheet, PDF (123/293 Pages) STMicroelectronics – Turbo Plus Series Fast Turbo 8032 MCU with USB and Programmable Logic

uPSD34xx
I²C interface
Table 56.
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
Bit
Symbol
R/W
Function
General Call flag
GC = 1 if the General Call address of 00h was received when
7
GC
R SIOE is in 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 I²C interrupt conditions listed
above. INTR must be cleared by firmware.
Transmission Mode flag
4
TX_MODE
R
TX_MODE = 1 whenever the SIOE is in Master-Transmitter or
Slave-Transmitter mode. TX_MODE = 0 when SIOE is in any
receiver mode.
Bus Busy flag
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 condition.
Bus Lost flag
2
BLOST
R BLOST is set when the SIOE is in Master mode and it looses
the arbitration process to another Master device on the bus.
Not Acknowledge Response flag
While SIOE is in Transmitter mode:
– After SIOE sends a byte, ACK_RESP = 1 whenever the
external I²C device receives the byte, but that device does
NOT assert an ackowledge signal (external device asserted
a high on SDA during the acknowledge bit-time).
– After SIOE sends a byte, ACK_RESP = 0 whenever the
1
ACK_RESP
R
external I²C device receives the byte, and that device DOES
assert an ackowledge signal (external device drove a low on
SDA during the acknowledge bit-time)
Note: If SIOE is in Master-Transmitter mode, and ACK_RESP
= 1 due to a Slave-Transmitter not sending an Acknowledge, a
STOP condition will not automatically be generated by the
SIOE. The STOP condition must 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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