MPC 555 Memory Controller and Chip Select
How Does Keyboard Know It’s Memory Map? #Bytes (256) Chip-Select 0 (CS0) CS Base(0xf0000000) processor Keyboard Chip Enable 0xf0000000 Data register Control register R 0xf0000004
MPC 555 Memory Controller
Memory Controller Block Diagram
Chip Select Based System Design CSx Device (Keyboard)
Chip Select with Peripheral ACS: Address to CS Setup CSNT: Chip Select Negation Time
Memory Controller Address Map
Chip Select Programming
CS Base Address Register bits 31 V Mapping is valid
CS Programming: Option Registers
Option Register bits
Address Match Logic
Example Device Keyboard/Device foo memory map: 0x001f 0000 to 0x00ff ffff CS1 programmed as: BR1[BA] 0x003e; OR1[AM] 0x01fe;