Knowledge Base

MMi99 controllers with Firmware versions 3.3 or earlier contain language dialect 9, and do not implement shadow memory. Later versions of MMi99 firmware, and all versions of MMi203, MMi201 and MMi200, implement shadow memory.

Writing shadow memory in MMi203

Shadow memory in the MMi203 is implemented using main Flash memory. Endurance is 10,000 writes or clears in totalShadowWrite takes up to 20mS per byte. ShadowClear takes up to 10mS per byte. During these times the SPLat processor can do nothing else (for example quadrature counting). We use a smart algorithm to avoid redundant writes and clears, making the process as fast as possible and reducing wear on the memory.

Writing shadow memory in MMi201 (legacy information)

Shadow memory in the MMi201 is implemented using a byte erasable EEPROM memory. Endurance is 10,000 writes or clears in any one byte. ShadowWrite takes up to 20mS per byte. ShadowClear takes up to 10mS per byte. During these times the SPLat processor can do nothing else (for example quadrature counting). We use a smart algorithm to avoid redundant writes and clears, making the process as fast as possible and reducing wear on the memory.

ShadowRead is very fast.

Downloading a program to the controller does not change the contents of shadow memory.