34.1 Description

The External Bus Interface (EBI) is designed to ensure the successful data transfer between several external devices and the ARM-based microcontroller. The Static Memory Controller (SMC) is part of the EBI.

The SMC handles several types of external memory and peripheral devices, such as SRAM, PSRAM, PROM, EPROM, EEPROM, LCD Module, NOR Flash and NAND Flash.

The SMC generates the signals that control the access to the external memory devices or peripheral devices. It has 4 chip selects, a 24-bit address bus, and a configurable 8 or 16-bit data bus. Separate read and write control signals allow for direct memory and peripheral interfacing. Read and write signal waveforms are fully adjustable.

The SMC can manage wait requests from external devices to extend the current access. The SMC is provided with an automatic Slow clock mode. In Slow clock mode, it switches from user-programmed waveforms to slow-rate specific waveforms on read and write signals. The SMC supports asynchronous burst read in Page mode access for page sizes up to 32 bytes.

The external data bus can be scrambled/unscrambled by means of user keys.