STMicroelectronics STM32F05 series User Manual

Inter-integrated circuit (I
2
C) interface RM0091
506/742 Doc ID 018940 Rev 1
● Configuring the maximum duration of t
LOW:SEXT
and t
LOW:MEXT
to 8 ms:
● Configuring the maximum duration of t
IDLE
to 50 µs
23.4.14 SMBus slave mode
This section is relevant only when SMBus feature is supported. Please refer to Section 23.3:
I2C implementation.
In addition to I2C slave transfer management (refer to Section 23.4.8: I2C slave mode)
some additional software flowcharts are provided to support SMBus.
SMBus Slave transmitter
When the IP is used in SMBus, SBC must be programmed to ‘1’ in order to allow the PEC
transmission at the end of the programmed number of data bytes. When the PECBYTE bit is
set, the number of bytes programmed in NBYTES[7:0] includes the PEC transmission. In
that case the total number of TXIS interrupts will be NBYTES-1 and the content of the
I2Cx_PECR register is automatically transmitted if the master requests an extra byte after
the NBYTES-1 data transfer.
Caution: The PECBYTE bit has no effect when the RELOAD bit is set.
Table 72. Examples of TIMEOUTA settings for various I2CCLK
frequencies
f
I2CCLK
TIMEOUTA[11:0]
bits
TIDLE
bit
TIMEOUTEN
bit
t
TIMEOUT
8 MHz 0x61 0 1 98 x 2048 x 125 ns = 25 ms
16 MHz 0xC3 0 1 196 x 2048 x 62.5 ns = 25 ms
48 MHz 0x249 0 1 586 x 2048 x 20.08 ns = 25 ms
Table 73. Examples of TIMEOUTB settings for various I2CCLK frequencies
f
I2CCLK
TIMEOUTB[11:0]
bits
TEXTEN bit
t
LOW:EXT
8 MHz 0x1F 1 32 x 2048 x 125 ns = 8 ms
16 MHz 0x3F 1 64 x 2048 x 62.5 ns = 8 ms
48 MHz 0xBB 1 188 x 2048 x 20.08 ns = 8 ms
Table 74. Examples of TIMEOUTA settings for various I2CCLK frequencies
f
I2CCLK
TIMEOUTA[11:0]
bits
TIDLE bit
TIMEOUTEN
bit
t
TIDLE
8 MHz 0x63 1 1 100 x 4 x 125 ns = 50 µs
16 MHz 0xC7 1 1 200 x 4 x 62.5 ns = 50 µs
48 MHz 0x257 1 1 600 x 4 x 20.08 ns = 50 µs

STMicroelectronics STM32F05 series Specifications

General

Brand	STMicroelectronics
Model	STM32F05 series
Category	Microcontrollers
Language	English