Memory Organization Microprocessor and Interfacing 261214 CPU 8088

Memory Organization Microprocessor and Interfacing 261214

CPU 8088 10 MHz 8/16 Bit 1 M RAM

CPU 80486 66 MHz 32 Bit 8 M RAM

Pentium 133 MHz 32 Bit 16 M RAM

Pentium MMX 200 MHz 32 Bit 48 M RAM

Pentium II 366 MHz 32 Bit 128 M RAM

Pentium M 1. 6 GHz 32 Bit 512 M RAM

Core 2 Duo 2. 0 GHz 32/64 Bit 4 G RAM

Core i 5 1. 33 – 1. 86 GHz 32/64 Bit 4 G RAM

What has changed the least?

MHz RAM CPU Bits

What does “Bits” mean?

A CPU “bits” is typically defined by: �ALU Size How many bits can be computed at one time? �Bus Size How many bits can be transferred on the bus? �Memory Address Size How many address bits are in the instruction?

How many bits Is this PIC CPU?

16 -bit operation on a 8 -bit CPU Microchip PIC 16 series . . . . 0017: BCF 03. 6 0018: CLRF 22 0019: MOVLW 01 001 A: MOVWF 21. . . . . 001 B: MOVLW 02 001 C: ADDWF 21, F 001 D: BTFSC 03. 0 001 E: INCF 22, F int 16 i; i=1; i = i+2;

. . . . 0017: BCF 03. 6 0018: CLRF 22 0019: MOVLW 01 001 A: MOVWF 21. . . . . 001 B: MOVLW 02 001 C: ADDWF 21, F 001 D: BTFSC 03. 0 001 E: INCF 22, F int 16 i; i=1; i = i+2; 0 1

16 -bit operation on a 16 -bit CPU Microchip PIC 24 series . . int 16 i; . . i=1; 00210: MOV #1, W 4 00212: MOV W 4, 802. . . . . i = i+2; 00214: MOV 802, W 4 00216: ADD W 4, #2, W 4 00218: MOV W 4, 802

Memory Limit of 32 bit Machines = 4 Giga Bytes

How to support bigger memory? 1. Upgrade to 64 -bit systems 64 -bit CPU 64 -bit OS

Limitation of moving to 64 -bit systems (Note: Today’s 64 bit support legacy 32 apps. So, migration is easier) Need 64 -bit Hardware Drivers Applications need to be re-compiled with a 64 -bit compiler

How to support bigger memory? 2. Expand the existing system (Adding more bits)

วธแกปญหาของ Intel Physical Address Extension (PAE) 4 bits 32 bits = 64 GB

PAE Support CPU with PAE (Since P-Pro) PAE Aware OS

Benefits of PAE �Backward Compatible Limitations n Taking advantage of the added memory still requires changes in the software

Memory Limit of 64 Bit Machines?

How big can we get? 1 kilobyte 1 megabyte 1 gigabyte 1 terabyte 1 petabyte 1 exabyte 1 zettabyte 1 yottabyte 1 xonabyte 1 wekabyte 1 vundabyte 1, 024 1, 048, 576 1, 073, 741, 824 1, 099, 511, 627, 776 1, 125, 899, 906, 842, 624 1, 152, 921, 504, 606, 846, 976 1, 180, 591, 620, 717, 411, 303, 424 1, 208, 925, 819, 614, 629, 174, 706, 176 1, 237, 940, 039, 285, 380, 274, 899, 124, 224 1, 267, 650, 600, 228, 229, 401, 496, 703, 205, 376 1, 298, 074, 214, 633, 706, 907, 132, 624, 082, 305, 024 264 = 18, 446, 744, 073, 709, 551, 616 ~ 18 exabyte

Amount of RAM (GB) in a typical computer About 4 TB in 2025 ��

64 -Bit Architectures IA-64 True 64 bit CPU AMD 64, EM 64 T Or X 86 -64 Hybrid 32/64 bit CPU

A hybrid 32/64 bit system �Has the benefits of a 64 -bit programs �Can also run older 32 -bit programs � 32 -Bit programs will not benefit from the 64 -bit architecture �Architecture not as clean as true 64 -bit systems

What is wrong with this call command? 0 x 500 คำสง 0 x 501 CALL 0 x 900 … … คำสงถดไป 0 x 900

K = 11 bit Maximum memory = 2^11 = 2 K Bytes

PIC 16 F 886 has 8 K Flash Memory: How do we access all of it? 7 4 3 0 PCLATH (F# 0 x 0 A) Bit 3 -4 in PCLATH are used for memory access Total Memory becomes 2^13 = 8 K Bytes

Creating a 13 bit memory address 13 OPCODE CALL or GOTO 4 3 7 11 10 0 k (Literal) 0 PCLATH 12 10 0 13 Bit Memory Address

12 10 0 2 K 2 K PIC Flash Memory is Divided in to 4 Pages of 2 KBytes

Fix this program 0 x 500 คำสง 0 x 501 CALL 0 x 900 … … คำสงถดไป 0 x 900

Address 0 x 900 exceeds 11 bits 12 10 0 0 x 900 = 0 1 0 0 0 0 0 x 01 0 x 100

12 10 0 0 x 900 = 0 1 0 0 0 0 0 x 01 0 x 100 0 x 4 FF BCF PCLATH, 4 0 x 500 BSF PCLATH, 3 0 x 501 CALL 0 x 100 … … คำสงถดไป 0 x 900