Functional Description
STV0684
3.5 Memory interface
Description
The memory control Block provides dedicated support for embedded SRAM, external SDRAM,
NAND, Smartmedia and Compact Flash (via SFP pins).
Embedded SRAM
● Full-speed random read/write access from the ST20 to embedded SRAM
● Full-speed embedded SRAM address generation for real-time data writes from the compression
engine, the Video Processor block, SPI, the audio block and the USB module
● Full-speed embedded SRAM address generation for data reads to the DMA out FIFO
Selection of the source/destination modules is managed by firmware.
External SDRAM
● ST20 memory mapped accesses to external SDRAM
● Full-speed embedded SDRAM address generation for real-time data writes from VDFIF (for VC
and VP modules) or DMA out FIFO
● Full-speed external SDRAM address generation/control to DMA out FIFO, TV FIFO, LCD FIFO
or VP FIFO’s
● Operation with PC100 (or better e.g. PC133) and JEDEC Standard No. 21-C compliant devices
and supports 64MB, 128MB, 256MB and 512MB parts with a 16-bit bus width
Mass storage media support
● Compact-flash support
● SmartMedia Card support
● NAND flash memory with a 512B+16 page organization, ECC done by hardware, 32Mbit to
1Gbit devices
● Support for Multi-Media card and Secure Digital with the SPI interface
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