SPRUJ17I March 2022 – August 2025 AM2631 , AM2631-Q1 , AM2632 , AM2632-Q1 , AM2634 , AM2634-Q1
The I2C module operates in byte data format. Each message put on the SDA line is 2 to 8-bits long. The number of messages that can be transmitted or received is unrestricted. The data is transferred with the most significant bit (MSB) first (Figure 13-8). Each message is followed by an acknowledge bit from the I2C if it is in receiver mode. The I2C module does not support little endian systems.
Figure 13-8 I2C Module Data Transfer
The first byte after a START condition (S) always consists of 8 bits that comprise either a 7-bit address plus the R/ W bit, or 8 data bits. The eighth bit, R/W, in the first byte determines the direction of the data. When the R/ W bit is 0, the controller writes (transmits) data to a selected peripheral device; when the R/ W bit is 1, the controller reads (receives) data from the peripheral device. In acknowledge mode, an extra bit dedicated for the acknowledgement (ACK) bit is inserted after each message.
The I2C module supports the following formats: