Why does each entry in the Data Match Table take up 4 bytes (32-bits) of memory space when each entry only contains 2 bytes (16-bits)?
A. The Data Match table “skips” every other word to maintain a constant offset for each corresponding Data RAM location. Each Data RAM location is a full 32-bits wide. The address of the Data RAM location is always 200 (hexadecimal) less than its corresponding Data Match Table entry. Because of this mapping, when writing to address 200h, the same 16-bit data will appear at both 200h and 202h. The effect of this mapping is that between the addresses of 200h to 3FFh the A1 bit of the address bus, which is internal to the DD-42900, is not used.
