st92f124 STMicroelectronics, st92f124 Datasheet - Page 263

• Manufacturer Part Number: st92f124
• Description: 8/16-bit Single Voltage Flash Mcu Family With Ram, E3 Tmemulated Eeprom, Can 2.0b And J1850 Blpd
• Manufacturer: STMicroelectronics

I
The following seven registers are used to handle
the interrupt and the DMA features:
– Interrupt Status Register I2CISR
– Interrupt Mask Register I2CIMR
– Interrupt Vector Register I2CIVR
– Receiver DMA Address Pointer Register
– Receiver DMA Transaction Counter Register
– Transmitter DMA Address Pointer Register
– Transmitter DMA transaction Counter Register
The interface can decode both addresses:
– Software programmable 7-bit General Call
– I
After a reset, the interface is disabled.
IMPORTANT:
1. To guarantee correct operation, before enabling
the peripheral (while I2CCR.PE=0), configure bit7
and bit6 of the I2COAR2 register according to the
internal clock INTCLK (for example 11xxxxxxb in
the range 14 - 30 MHz).
2. Bit7 of the I2CCR register must be cleared.
10.8.3.1 Mode Selection
In I
following modes:
– Master transmitter/receiver
– Slave transmitter/receiver
By default, it operates in slave mode.
This interface automatically switches from slave to
master after a start condition is generated on the
bus and from master to slave in case of arbitration
loss or stop condition generation.
In Master mode, it initiates a data transfer and
generates the clock signal. A serial data transfer
always begins with a start condition and ends with
a stop condition. Both start and stop conditions are
generated in master mode by software.
In Slave mode, it is able to recognize its own ad-
dress (7 or 10-bit), as stored in the I2COAR1 and
I2COAR2 registers and (when the I2CCR.ENGC
2
C BUS INTERFACE (Cont’d)
I2CRDAP
I2CRDC
I2CTDAP
I2CTDC
address
register in 7-bit address mode or stored in
I2COAR1 and I2COAR2 registers in 10-bit ad-
dress mode.
2
2
C address stored by software in the I2COAR1
C mode, the interface can operate in the four
bit is set) the General Call address (stored in
I2CADR register). It never recognizes the Start
Byte (address byte 01h) whatever its own address
is.
Data and addresses are transferred in 8 bits, MSB
first. The first byte(s) following the start condition
contain the address (one byte in 7-bit mode, two
bytes in 10-bit mode). The address is always
transmitted in master mode.
A 9th clock pulse follows the 8 clock cycles of a
byte transfer, during which the receiver must send
an
Acknowledge is enabled and disabled by software.
Refer to
acknowledge
Figure
127.
bit
I2C BUS INTERFACE
to
the
transmitter.
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