Users Manual
Table Of Contents
- 34. IrDA Interface
- 35. I2C-bus Interface (RIICa)
- 35.1 Overview
- 35.2 Register Descriptions
- 35.2.1 I2C-bus Control Register 1 (ICCR1)
- 35.2.2 I2C-bus Control Register 2 (ICCR2)
- 35.2.3 I2C-bus Mode Register 1 (ICMR1)
- 35.2.4 I2C-bus Mode Register 2 (ICMR2)
- 35.2.5 I2C-bus Mode Register 3 (ICMR3)
- 35.2.6 I2C-bus Function Enable Register (ICFER)
- 35.2.7 I2C-bus Status Enable Register (ICSER)
- 35.2.8 I2C-bus Interrupt Enable Register (ICIER)
- 35.2.9 I2C-bus Status Register 1 (ICSR1)
- 35.2.10 I2C-bus Status Register 2 (ICSR2)
- 35.2.11 Slave Address Register Ly (SARLy) (y = 0 to 2)
- 35.2.12 Slave Address Register Uy (SARUy) (y = 0 to 2)
- 35.2.13 I2C-bus Bit Rate Low-Level Register (ICBRL)
- 35.2.14 I2C-bus Bit Rate High-Level Register (ICBRH)
- 35.2.15 I2C-bus Transmit Data Register (ICDRT)
- 35.2.16 I2C-bus Receive Data Register (ICDRR)
- 35.2.17 I2C-bus Shift Register (ICDRS)
- 35.3 Operation
- 35.4 SCL Synchronization Circuit
- 35.5 SDA Output Delay Function
- 35.6 Digital Noise Filters
- 35.7 Address Match Detection
- 35.8 Automatic Low-Hold Function for SCL
- 35.9 Arbitration-Lost Detection Functions
- 35.10 Start Condition/Restart Condition/Stop Condition Generating Function
- 35.11 Bus Hanging
- 35.12 SMBus Operation
- 35.13 Interrupt Sources
- 35.14 Initialization of Registers and Functions When a Reset is Applied or a Condition is Detected
- 35.15 Event Link Function (Output)
- 35.16 Usage Notes
- 36. CAN Module (RSCAN)
R01UH0823EJ0110 Rev.1.10 Page 1185 of 1852
Nov 30, 2020
RX23W Group 35. I
2
C-bus Interface (RIICa)
Condition for arbitration-lost during NACK transmission
• When the internal SDA output level does not match the SDA0 line (ACK is received) during transmission of NACK
(ICMR3.ACKBT bit = 1)
35.9.3 Slave Arbitration-Lost Detection (SALE Bit)
The RIIC has a function to cause arbitration to be lost if the data for transmission (i.e. the internal SDA output level) and
the level on the SDA0 line do not match (the high output as the internal SDA output; i.e. the SDA0 pin is in the high-
impedance state and the low is detected on the SDA0 line in slave transmit mode). This arbitration-lost detection
function is mainly used when transmitting a UDID (Unique Device Identifier) over an SMBus.
When it loses slave arbitration, the RIIC is immediately released from the slave-matched state and enters slave receive
mode. This function can detect conflicts of data during transmission of UDIDs over an SMBus and eliminate subsequent
redundant processing (processing for the transmission of FFh).
The RIIC detects slave arbitration-lost when the following condition is met with the ICFER.SALE bit set to 1 (slave
arbitration-lost detection enabled).
Condition for slave arbitration-lost
• When transmit data excluding acknowledgment bit (internal SDA output level) does not match the SDA0 line in
slave transmit mode (bits MST and TRS in the ICCR2 register are 01b)
Figure 35.36 Example of Slave Arbitration-Lost Detection (SALE = 1)
8234567
Data
8234567
Data
9
9
1
Transmit data mismatch
(Arbitration lost)
Release SCL/SDA
2 3 4
2 3 4 5
0
6 7 8 9
5
1
1
1
1 23456
Data
3456
[Conflict during data transmission]
ACK
ACK
ACK
Write data to ICDRT register
Clear AL flag to 0
TRS
AL
MST
BBSY
TDRE
SCL0
SDA0
SCL0
SDA0