"0x1000" - 1 õppematerjal

Mictrocontroller Week 03

then to the chip select pins, such that only one chip will be active for each input combination and all chips are used. The data output pins of the memory modules are connected to OR gates to provide the final 8-bit output. PROM (Programmable Read Only Memory) With 10 pins or 10 bits, a PROM can address 210 which is 1024 memory locations = 1 kB Four PROM chips will have 4 kB of addressable memory Microprocessor (12 address bits) can access 212 = 4096 = 4 kB locations (0x1000) Connect MP address lines A9-A0 to PROM's A9-A0 pins But what do we do with MP's A11 and A10 address lines? Connect by the below ==> each PROM chip will be selected upon the state (1 or 0) of MP's A11 and A10 lines So addresses 00 00 0000 0000 - 00 11 1111 1111 (0x000-0x3FF) 01 00 0000 0000 - 01 11 1111 1111 (0x400-0x7FF) 10 00 0000 0000 - 10 11 1111 1111 (0x800-0xBFF) 11 00 0000 0000 - 11 11 1111 1111 (0xC00-0xFFF)