GD32F10x User Manual
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source or pull-up resistor. When the bus is free, both lines are HIGH. The output stages of
devices connected to the bus must have an open-drain or open-collect to perform the wired-
AND function. Data on the I2C-bus can be transferred at rates of up to 100 Kbit/s in the
standard-mode and up to 400 Kbit/s in the fast-mode. Due to the variety of different
technology devices (CMOS, NMOS, bipolar) that can be connected to the I2C-bus, the
voltage levels of the logical ‘0’ (LOW) and ‘1’ (HIGH) are not fixed and depend on the
associated level of V
DD
.
17.3.2.
Data validation
The data on the SDA line must be stable during the HIGH period of the clock. The HIGH or
LOW state of the SDA line can only change when the clock signal on the SCL line is LOW
(see
). One clock pulse is generated for each data bit transferred.
Figure 17-2. Data validation
SDA
SCL
17.3.3.
START and STOP signal
All transmissions begin with a START and are terminated by a STOP (see
). A HIGH to LOW transition on the SDA line while SCL is HIGH
defines a START signal. A LOW to HIGH transition on the SDA line while SCL is HIGH defines
a STOP signal.
Figure 17-3. START and STOP condition
SDA
SCL
SDA
SCL
START
STOP
Summary of Contents for GD32F10 Series
Page 63: ...GD32F10x User Manual 63 programmed during the chip production ...
Page 117: ...GD32F10x User Manual 117 010 1 0 011 0 9 ...
Page 416: ...GD32F10x User Manual 416 shadow register updates every update event ...
Page 427: ...GD32F10x User Manual 427 value ...
Page 518: ...GD32F10x User Manual 518 These bits are not used in SPI mode ...