Table 231. Smbus Timeout Specifications; Figure 299. Timeout Intervals For T; Low:sext , T Low:mext - ST STM32WL55JC Reference Manual

RM0453
Caution: Changing the TIMEOUTA and TIDLE configuration is not allowed when the TIMEOUTEN is
set.
SMBus:
34.4.13
This section is relevant only when SMBus feature is supported. Refer to
implementation.
•
Configuring the maximum duration of t
Table 233. Examples of TIMEOUTA settings for various I2CCLK frequencies
f
I2CCLK
8 MHz
16 MHz
•
Configuring the maximum duration of t
Table 234. Examples of TIMEOUTB settings for various I2CCLK frequencies
f
I2CCLK
8 MHz
16 MHz
• Configuring the maximum duration of t
Table 235. Examples of TIMEOUTA settings for various I2CCLK frequencies
f
I2CCLK
8 MHz
16 MHz
34.4.14 SMBus slave mode
This section is relevant only when the SMBus feature is supported. Refer to
I2C implementation.
In addition to I2C slave transfer management (refer to
some additional software flowcharts are provided to support the 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 is NBYTES-1 and the content of the
I2C_PECR register is automatically transmitted if the master requests an extra byte after the
NBYTES-1 data transfer.
I2C_TIMEOUTR register configuration examples
(max t
TIMEOUTA[11:0] bits
0x61
0xC3
TIMEOUTB[11:0] bits
0x1F
0x3F
TIMEOUTA[11:0] bits
0x63
0xC7
RM0453 Rev 2
Inter-integrated circuit (I2C) interface
to 25 ms:
TIMEOUT
= 25 ms)
TIMEOUT
TIDLE bit TIMEOUTEN bit
0 1
0 1
and t
LOW:SEXT
TEXTEN bit
1
1
to 50 µs
IDLE
(max t = 50 µs)
IDLE
TIDLE bit TIMEOUTEN bit
1 1
1 1
Section 34.4.8: I2C slave
Section 34.3: I2C
t
TIMEOUT
98 x 2048 x 125 ns = 25 ms
196 x 2048 x 62.5 ns = 25 ms
to 8 ms:
LOW:MEXT
t
LOW:EXT
32 x 2048 x 125 ns = 8 ms
64 x 2048 x 62.5 ns = 8 ms
t
TIDLE
100 x 4 x 125 ns = 50 µs
200 x 4 x 62.5 ns = 50 µs
Section 34.3:
mode)
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