MTK I2C / SCCB Controller

I2C / SCCB Controller
I2C (Inter-IC) /SCCB (Serial Camera Control Bus) is a two-wire serial interface.  The two signals are SCL and SDA. SCL is a clock signal that is driven by the master.  SDA is a bi-directional data signal that can be driven by either the master or the slave.  This generic controller supports the master role and conforms to the I2C specification.

1) Feature Support
I2C compliant master mode operation
Adjustable clock speed for LS/FS mode operation.
7bit/10 bit addressing support.
High Speed mode support.
Slave Clock Extension support.
START/STOP/REPEATED START condition
Manual/DMA Transfer Mode
Multi write per transfer (up to 8 data bytes for non dma mode and 255 data bytes for dma mode)
Multi read per transfer (up to 8 data bytes for non dma mode and 255 data bytes for dma mode)
Multi transfer per transaction (up to 256 write transfers or 256 read transfers with dma mode)
DMA mode with Fifo Flow Control and bus signal holding
Combined format transfer with length change capability.
Active drive / wired-and I/O configuration

2)Manual/DMA Transfer Mode
The controller offers 2 types of transfer mode, Manual and DMA.
When Manual mode is selected, in addition to the slave address register, the controller has a built-in 8byte deep FIFO which allows mcu to prepare up to 8 bytes of data for a write transfer, or read up to 8 bytes of data for a read transfer.
When DMA mode is enabled, the data to and from the FIFO is controlled via DMA transfer and can therefore support up to 255 bytes of consecutive read or write, with the data read from or write to another memory space. When DMA mode is enabled, flow control mechanism is also implemented to hold the bus clk when FIFO underflow or overflow condition is encountered.

3) Transfer format support
This controller has been designed to be as generic as possible in order to support a wide range of devices that may utilize different combinations of transfer formats. Here are the transfer format types that can be supported through different software configuration:
(Wording convention note:  
 transfer = anything encapsulated within a Start and Stop or Repeated Start.
 transfer length = the number of bytes within the transfer.
 transaction = this is the top unit. Everything combined equals 1 transaction.
 Transaction length = the number of transfers to be conducted.