ST72F321J ST Microelectronics, ST72F321J Datasheet - Page 118

• Manufacturer Part Number: ST72F321J
• Description: 8-BIT MCU
• Manufacturer: ST Microelectronics

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DataSheet
ST72321J
I
10.7.7 Register Description
I
Read / Write
Reset Value: 0000 0000 (00h)
Bit 7:6 = Reserved. Forced to 0 by hardware.
Bit 5 = PE Peripheral enable.
This bit is set and cleared by software.
0: Peripheral disabled
1: Master/Slave capability
Notes:
– When PE=0, all the bits of the CR register and
– When PE=1, the corresponding I/O pins are se-
– To enable the I
Bit 4 = ENGC Enable General Call.
This bit is set and cleared by software. It is also
cleared by hardware when the interface is disa-
bled (PE=0). The 00h General Call address is ac-
knowledged (01h ignored).
0: General Call disabled
1: General Call enabled
Bit 3 = START Generation of a Start condition .
This bit is set and cleared by software. It is also
cleared by hardware when the interface is disa-
bled (PE=0) or when the Start condition is sent
(with interrupt generation if ITE=1).
– In master mode:
– In slave mode:
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2
2
C BUS INTERFACE (Cont’d)
C CONTROL REGISTER (CR)
the SR register except the Stop bit are reset. All
outputs are released while PE=0
lected by hardware as alternate functions.
TWICE with PE=1 as the first write only activates
the interface (only PE is set).
0: No start generation
1: Repeated start generation
0: No start generation
1: Start generation when the bus is free
7
0
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0
PE
2
C interface, write the CR register
ENGC START ACK
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STOP
ITE
0
Bit 2 = ACK Acknowledge enable.
This bit is set and cleared by software. It is also
cleared by hardware when the interface is disa-
bled (PE=0).
0: No acknowledge returned
1: Acknowledge returned after an address byte or
Bit 1 = STOP Generation of a Stop condition .
This bit is set and cleared by software. It is also
cleared by hardware in master mode. Note: This
bit is not cleared when the interface is disabled
(PE=0).
– In master mode:
– In slave mode:
Bit 0 = ITE Interrupt enable.
This bit is set and cleared by software and cleared
by hardware when the interface is disabled
(PE=0).
0: Interrupts disabled
1: Interrupts enabled
Refer to
events and the interrupt.
SCL is held low when the ADD10, SB, BTF or
ADSL flags or an EV6 event (See
tected.
0: No stop generation
1: Stop generation after the current byte transfer
or after the current Start condition is sent. The
STOP bit is cleared by hardware when the Stop
condition is sent.
0: No stop generation
1: Release the SCL and SDA lines after the cur-
rent byte transfer (BTF=1). In this mode the
STOP bit has to be cleared by software.
a data byte is received
Figure 64
for the relationship between the
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