Tài liệu Microprocessor System Design pdf

University of Technology 1 Microprocessor System Design BÙI QUỐC BẢO (buiquocbao@hcmut.edu.vn) University of Technology 2 Outline • Address decoding • Chip select • Memory configurations University of Technology 3 MEMORY INTERFACE When Memory is selected? MEMORY D7 - D0 A19 - A0 RD WR Simplified Drawing of 8088 Minimum Mode D7 - D0 A19 - A0 MEMR MEMW cs University of Technology 4 Minimum Mode MEMORY D7 - D0 A19 - A0 RD WR Simplified Drawing of 8088 Minimum Mode D7 - D0 A19 - A0 MEMR MEMW CS 2 20 bytes or 1MB University of Technology 5 What are the memory locations of a 1MB (2 20 bytes) Memory? A19 to A0 (HEX) AAAA 1111 9876 AAAA 1111 5432 AAAA 1198 1000 AAAA 7654 AAAA 3210 00000 0000 0000 0000 0000 0000 FFFFF 1111 1111 1111 1111 1111 Example: 34FD0 0011 0100 11111 1101 0000 University of Technology 6 Interfacing a 1MB Memory to the 8088 Microprocessor 2300000 00001 10000 10001 10002 10003 10004 10005 10006 10007 10008 95 : : 45 98 27 39 42 88 07 F4 8A : : 20020 20021 20022 20023 FFFFD FFFFE FFFFF 29 12 7D 13 19 25 36 : : : : : : : : A19 A0 : D7 D0 : RD WR A19 A0 : D7 D0 : MEMR MEMW XXXX BP ES DS SS CX BX AX XXXX XXXX XXXX 2000 0000 0023 3F1C FCA1 SP DX XXXX CS SI XXXX XXXXIP XXXXDI CS University of Technology 7 Instead of Interfacing 1MB, what will happen if you interface a 512KB Memory? University of Technology 8 What are the memory locations of a 512KB (2 19 bytes) Memory? A18 to A0 (HEX) AAAA 1111 9876 AAAA 1111 5432 AAAA 1198 1000 AAAA 7654 AAAA 3210 00000 0000 0000 0000 0000 0000 7FFFF 0111 1111 1111 1111 1111 University of Technology 9 Interfacing a 512KB Memory to the 8088 Microprocessor A18 A0 : D7 D0 : MEMR MEMWXXXX BP ES DS SS CX BX AX XXXX XXXX XXXX 2000 0000 0023 3F1C FCA1 SP DX XXXX CS SI XXXX XXXXIP XXXXDI 2300000 00001 95 : : 20020 20021 20022 20023 7FFFD 7FFFE 7FFFF 29 12 7D 13 19 25 36 : : : : : : A18 A0 : D7 D0 : RD WR CS A19 What do we do with A19? University of Technology 10 What if you want to read physical address A0023? A18 A0 : D7 D0 : MEMR MEMWXXXX BP ES DS SS CX BX AX XXXX XXXX XXXX A000 0000 0023 3F1C FCA1 SP DX XXXX CS SI XXXX XXXXIP XXXXDI 2300000 00001 95 : : 20020 20021 20022 20023 7FFFD 7FFFE 7FFFF 29 12 7D 13 19 25 36 : : : : : : A18 A0 : D7 D0 : RD WR CS A19 [...]... to the 8088 Microprocessor A19 A18 : A18 : A0 A0 D7 : D7 : D0 D0 MEMR 8088 Minimum Mode RD MEMW 512KB #2 WR CS A18 : A0 D7 : D0 512KB #1 RD WR CS University of Technology 30 Interfacing one 512K Memory Chips to the 8088 Microprocessor A19 A18 : A18 : A0 A0 D7 : D7 : D0 D0 MEMR 8088 Minimum Mode RD MEMW 512KB WR CS University of Technology 31 Interfacing one 512K Memory Chips to the 8088 Microprocessor. .. 95 23 7FFFF 7FFFE 7FFFD 12 98 2C : 33 45 92 A3 : D4 97 : 20023 20022 20021 20020 : 00001 00000 University of Technology 13 Interfacing two 512KB Memory to the 8088 Microprocessor • Problem: đụng độ bus (bus conflict) Hai RAM sẽ xuất dữ liệu cùng lúc khi VXL thực hiện lệnh đọc bộ nhớ • Solution: dùng A19 làm bộ phân xử bus (bus arbiter), trong trường hợp này có thể gọi là bộ giải mã địa chỉ (address... so even if the 8088 microprocessor outputs a logic “1”, the memory cannot “see” this University of Technology 11 What if you want to read physical address 20023? A18 to A0 (HEX) AAAA 1111 9876 AAAA 1111 5432 AAAA 1198 1000 AAAA 7654 AAAA 3210 20023 0010 0000 0000 0010 0011 For memory it is the same as previous one University of Technology 12 Interfacing two 512KB Memory to the 8088 Microprocessor AX... 8088 Minimum Mode RD MEMW 512KB WR CS University of Technology 32 Interfacing one 512K Memory Chips to the 8088 Microprocessor (version 3) A19 A18 : A18 : A0 A0 D7 : D7 : D0 D0 MEMR 8088 Minimum Mode RD MEMW 512KB WR CS University of Technology 33 Interfacing four 256K Memory Chips to the 8088 Microprocessor A17 : A0 D7 : D0 RD WR A19 A18 CS A17 A17 : A0 D7 : D0 MEMR MEMW 8088 Minimum Mode 256KB #4 :... 00001 95 CS 00000 23 7FFFF 7FFFE 7FFFD 12 98 2C : 33 A18 : A0 D7 : D0 RD WR CS : 20023 20022 20021 20020 : 00001 00000 45 92 A3 : D4 97 University of Technology 17 Interfacing two 512KB Memory to the 8088 Microprocessor AX 3F1C A19 BX CX 0023 0000 A18 DX FCA1 A0 A0 D7 D7 CS XXXX SS DS XXXX 2000 ES XXXX BP SP XXXX XXXX SI DI XXXX XXXX IP XXXX 7FFFF : : D0 MEMR MEMW A18 : : D0 RD WR CS A18 : A0 D7 : D0 RD... 7D 20021 20020 12 29 : 00001 00000 7FFFF 7FFFE 7FFFD : 20023 20022 20021 20020 : 00001 00000 : 95 23 12 98 2C : 33 45 92 A3 : D4 97 University of Technology 18 Interfacing two 512KB Memory to the 8088 Microprocessor AX 3F1C A19 A19 BX 0023 A18 A18 CX DX 0000 FCA1 : A0 CS XXXX SS XXXX DS ES 2000 XXXX XXXX XXXX SI DI XXXX XXXX IP XXXX 36 A18 7FFFE 25 : A0 : A0 7FFFD 19 : D7 : D7 : D7 : D0 D0 D0 MEMR RD... University of Technology 24 Full Decoding A19 to A0 (HEX) AAAA 1111 9876 AAAA 1111 5432 AAAA 1198 1000 AAAA 7654 AAAA 3210 00000 0000 0000 0000 0000 0000 7FFFF 0111 1111 1111 1111 1111 Therefore if the microprocessor outputs an address between 00000 to 7FFFF, whose A19 is a logic “0”, the memory chip will not be selected University of Technology 25 Partial Decoding AX BX 3F1C 0023 CX 0000 DX FCA1 CS... thể gọi là bộ giải mã địa chỉ (address decoder) • Khi A19 = 0, bộ nhớ thấp hơn được cho phép, bộ nhớ cao bị cấm Tương tự khi A19 = 1 University of Technology 14 Interfacing two 512KB Memory to the 8088 Microprocessor AX 3F1C A19 BX 0023 A18 CX 0000 : DX FCA1 A0 A0 D7 D7 CS XXXX SS XXXX DS 2000 ES XXXX : 7FFFF 36 A18 7FFFE 25 : 7FFFD 19 : : 20023 13 20022 7D 20021 12 20020 29 : SP XXXX : : WR 00001 95... AAAA 3210 00000 0000 0000 0000 0000 0000 7FFFF 0111 1111 1111 1111 1111 80000 1000 0000 0000 0000 0000 FFFFF 1111 1111 1111 1111 1111 University of Technology 16 Interfacing two 512KB Memory to the 8088 Microprocessor AX BX 3F1C 0023 A19 A18 CX 0000 : DX FCA1 A0 A0 CS XXXX SS XXXX D7 : D7 : DS ES 2000 XXXX D0 D0 XXXX XXXX SI DI XXXX XXXX IP XXXX 36 25 : MEMR MEMW BP SP A18 7FFFF 7FFFE 7FFFD 19 : 20023... 8088 Minimum Mode 256KB #4 : A0 D7 : D0 RD WR 256KB #3 CS A17 : A0 D7 : D0 RD WR 256KB #2 CS A17 : A0 D7 : D0 RD WR 256KB #1 University of Technology 34 CS Interfacing four 256K Memory Chips to the 8088 Microprocessor A17 : A0 D7 : D0 RD WR A19 A18 CS A17 A17 : A0 D7 : D0 MEMR MEMW 8088 Minimum Mode 256KB #4 : A0 D7 : D0 RD WR 256KB #3 CS A17 : A0 D7 : D0 RD WR 256KB #2 CS A17 : A0 D7 : D0 RD WR 256KB . University of Technology 1 Microprocessor System Design BÙI QUỐC BẢO (buiquocbao@hcmut.edu.vn) University of Technology. 14 Interfacing two 512KB Memory to the 8088 Microprocessor • Problem: đụng độ bus (bus conflict). Hai RAM sẽ xuất dữ liệu cùng lúc khi VXL thực hiện lệnh đọc