SCPS200E July   2009  – April 2019 TCA9555

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  4. 4 Revision History
  5. 5 Description (continued)
  6. 6 Pin Configuration and Functions
    1.     Pin Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 I2C Interface Timing Requirements
    7. 7.7 Switching Characteristics
    8. 7.8 Typical Characteristics
  8. 8 Parameter Measurement Information
  9. 9 Detailed Description
    1. 9.1 Overview
    2. 9.2 Functional Block Diagram
    3. 9.3 Feature Description
      1. 9.3.1 5-V Tolerant I/O Ports
      2. 9.3.2 Hardware Address Pins
      3. 9.3.3 Interrupt (INT) Output
    4. 9.4 Device Functional Modes
      1. 9.4.1 Power-On Reset (POR)
      2. 9.4.2 Powered-Up
    5. 9.5 Programming
      1. 9.5.1 I/O Port
      2. 9.5.2 I2C Interface
        1. 9.5.2.1 Bus Transactions
          1. 9.5.2.1.1 Writes
          2. 9.5.2.1.2 Reads
      3. 9.5.3 Device Address
      4. 9.5.4 Control Register and Command Byte
    6. 9.6 Register Maps
      1. 9.6.1 Register Descriptions
  10. 10Application and Implementation
    1. 10.1 Application Information
    2. 10.2 Typical Application
      1. 10.2.1 Design Requirements
      2. 10.2.2 Detailed Design Procedure
        1. 10.2.2.1 Calculating Junction Temperature and Power Dissipation
        2. 10.2.2.2 Minimizing ICC When I/O Is Used to Control LED
        3. 10.2.2.3 Pull-Up Resistor Calculation
      3. 10.2.3 Application Curves
  11. 11Power Supply Recommendations
  12. 12Layout
    1. 12.1 Layout Guidelines
    2. 12.2 Layout Example
  13. 13Device and Documentation Support
    1. 13.1 Documentation Support
      1. 13.1.1 Related Documentation
    2. 13.2 Receiving Notification of Documentation Updates
    3. 13.3 Community Resources
    4. 13.4 Trademarks
    5. 13.5 Electrostatic Discharge Caution
    6. 13.6 Glossary
  14. 14Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

9.5.4 Control Register and Command Byte

Following the successful acknowledgment of the address byte, the bus master sends a command byte shown in Table 3, that is stored in the control register in the TCA9555. Three bits of this data byte state the operation (read or write) and the internal register (input, output, polarity inversion, or configuration) that is affected. This register can be written or read through the I2C bus. The command byte is sent only during a write transmission.

When a command byte has been sent, the register that was addressed continues to be accessed by reads until a new command byte has been sent. Figure 33 shows the control register bits.

TCA9555 cntrl_reg_cps200.gifFigure 33. Control Register Bits

Table 3. Command Byte

CONTROL REGISTER BITS COMMAND
BYTE (HEX)		 REGISTER PROTOCOL POWER-UP
DEFAULT
B2 B1 B0
0 0 0 0x00 Input Port 0 Read byte xxxx xxxx
0 0 1 0x01 Input Port 1 Read byte xxxx xxxx
0 1 0 0x02 Output Port 0 Read-write byte 1111 1111
0 1 1 0x03 Output Port 1 Read-write byte 1111 1111
1 0 0 0x04 Polarity Inversion Port 0 Read-write byte 0000 0000
1 0 1 0x05 Polarity Inversion Port 1 Read-write byte 0000 0000
1 1 0 0x06 Configuration Port 0 Read-write byte 1111 1111
1 1 1 0x07 Configuration Port 1 Read-write byte 1111 1111