JAJSI83H May 2012 – September 2024 TCA9548A
PRODUCTION DATA
Following the successful acknowledgment of the address byte, the bus controller sends a command byte that is stored in the control register in the TCA9548A (see Figure 7-6). This register can be written and read via the I2C bus. Each bit in the command byte corresponds to a SCn/SDn channel and a high (or 1) selects this channel. Multiple SCn/SDn channels may be selected at the same time. When a channel is selected, the channel becomes active after a stop condition has been placed on the I2C bus. This makes sure that all SCn/SDn lines are in a high state when the channel is made active, so that no false conditions are generated at the time of connection. A stop condition always must occur immediately after the acknowledge cycle. If multiple bytes are received by the TCA9548A, it saves the last byte received.
Table 7-2 shows the TCA9548A Command Byte Definition.
CONTROL REGISTER BITS | COMMAND | |||||||
---|---|---|---|---|---|---|---|---|
B7 | B6 | B5 | B4 | B3 | B2 | B1 | B0 | |
X | X | X | X | X | X | X | 0 | Channel 0 disabled |
1 | Channel 0 enabled | |||||||
X | X | X | X | X | X | 0 | X | Channel 1 disabled |
1 | Channel 1 enabled | |||||||
X | X | X | X | X | 0 | X | X | Channel 2 disabled |
1 | Channel 2 enabled | |||||||
X | X | X | X | 0 | X | X | X | Channel 3 disabled |
1 | Channel 3 enabled | |||||||
X | X | X | 0 | X | X | X | X | Channel 4 disabled |
1 | Channel 4 enabled | |||||||
X | X | 0 | X | X | X | X | X | Channel 5 disabled |
1 | Channel 5 enabled | |||||||
X | 0 | X | X | X | X | X | X | Channel 6 disabled |
1 | Channel 6 enabled | |||||||
0 | X | X | X | X | X | X | X | Channel 7 disabled |
1 | Channel 7 enabled | |||||||
0 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | No channel selected, power-up/reset default state |