"The DTC and DMAC are peripherals found on a range of H8 and H8S microcontrollers. They both serve the purpose of transferring data to and from memory and peripherals, independently of CPU control.
A DMA channel is a dedicated piece of hardware that interfaces its own dedicated bus to the Internal Address and Data Bus for the purpose of transferring data. Due to this, the number of DMA channels available is limited to 2 to 4, depending on the mode of operation. The DTC is a slightly slower pseudo DMAthat is configured and run from on chip RAM. The number of DTC channels is limited by the size of on chip RAM.
The transfer of the user-data is just as fast on the DTC, but there are virtual-register transfers at the beginning and end of each transfer, which results in a slight performance overhead. Once the DTC registers have been configured the peak transfer rate of the DTC and DMA is the same. The DTC requires 2 Bytes of ROM and 12 Bytes of RAM per channel used."
|H8S/2258, 2239, 2238, 2237, 2227|