Laptop User Manual
S3C2440A RISC MICROPROCESSOR IIC-BUS INTERFACE
20-11
IIC-BUS INTERFACE SPECIAL REGISTERS
MULTI-MASTER IIC-BUS CONTROL (IICCON) REGISTER
Register Address R/W Description Reset Value
IICCON 0x54000000 R/W IIC-Bus control register 0x0X
IICCON Bit Description Initial State
Acknowledge generation
(1)
[7] IIC-bus acknowledge enable bit.
0 : Disable
1 : Enable
In Tx mode, the IICSDA is free in the ack time.
In Rx mode, the IICSDA is L in the ack time.
0
Tx clock source selection [6] Source clock of IIC-bus transmit clock prescaler
selection bit.
0 : IICCLK = f
PCLK
/16
1 : IICCLK = f
PCLK
/512
0
Tx/Rx Interrupt
(5)
[5] IIC-Bus Tx/Rx interrupt enable/disable bit.
0 : Disable, 1 : Enable
0
Interrupt pending flag
(2) (3)
[4] IIC-bus Tx/Rx interrupt pending flag. This bit
cannot be written to 1. When this bit is read as 1,
the IICSCL is tied to L and the IIC is stopped. To
resume the operation, clear this bit as 0.
0 : 1) No interrupt pending (when read).
2) Clear pending condition &
Resume the operation (when write).
1 : 1) Interrupt is pending (when read)
2) N/A (when write)
0
Transmit clock value
(4)
[3:0] IIC-Bus transmit clock prescaler.
IIC-Bus transmit clock frequency is determined by
this 4-bit prescaler value, according to the
following formula:
Tx clock = IICCLK/(IICCON[3:0]+1).
Undefined
Notes:
1. Interfacing with EEPROM, the ack generation may be disabled before reading the last data in order to generate the
STOP condition in Rx mode.
2. An IIC-bus interrupt occurs 1) when a 1-byte transmits or receive operation is completed, 2) when a general call or a slave
address match occurs, or 3) if bus arbitration fails.
3. To adjust the setup time of SDA before SCL rising edge, IICDS has to be written before clearing the IIC interrupt
pending bit.
4. IICCLK is determined by IICCON[6].
Tx clock can vary by SCL transition time.
When IICCON[6]=0, IICCON[3:0]=0x0 or 0x1 is not available.
5. If the IICCON[5]=0, IICCON[4] does not operate correctly.
So, It is recommended that you should set IICCON[5]=1, although you does not use the IIC interrupt.