Matakuliah
Tahun
Versi
: H0194/ Aplikasi Mikroprosesor dan Interfacing
: 2005
: 1.0
Pertemuan 2
Interface Mikroprosesor dan
Memory
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• Menjelaskan interface mikroprosesor
dengan memori dan aspek-aspeknya
2
Outline Materi
•
•
•
•
•
•
Address Decoding
Direct Memory Access (DMA)
Bank Switching
Extended Memory
Expanded Memory
Virtual Memory
3
Address Decoding
• Memory Addresing
A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1A0
0
0
0
0
0
0
0
0 0
0
0 0 0 0 0 0
0000h
0
0
0
1
1
1
1
1 1
1
1 1 1 1 1 1
1FFFh
0
0
1
0
0
0
0
0 0
0
0 0 0 0 0 0
2000h
0
0
1
1
1
1
1
1 1
1
1
3FFFh
RAM
ROM
1 1 1 1 1
0000
RAM
8KByte
1FFF
2000
Bisa digunakan
sebagai linier Selection
ROM
langsung ke pin address
pada IC ROM dan RAM
8KByte
3FFF
4
Address Decoding
• Linear Selection Addressing
Address Bus (A15-A0)
CPU
Data Bus
Control Bus
A12-A0
WE
A13
A12-A0
DB
DB
OE
OE
CS
CS
ROM
8K
A13
RAM
8K
5
Address Decoding
• Fully-Decoded Addresing
CPU
A11-A0
A11-A0
DB
DB
A14
WE
DB
A11-A0
WE
OE
OE
OE
OE
CS
CS
CS
CS
ROM
4K
A15
A11-A0
ROM
4K
G
Y3 Y2 Y1 Y0
A13 A12
RAM
4K
DB
RAM
4K
DECODER
2 to 4
6
Address Decoding
• I/O & Memory Addressing
A15 A14 A13 A12 A11 A10 A9 A8 A7 A6 A5 A4 A3 A2 A1A0
0
0
0
0
0
0
0
0 0
0
0 0 0 0 0 0
0
0
0
1
1
1
1
1 1
1
1 1 1 1 1 1
0
0
1
0
0
0
0
0 0
0
0 0 0 0 0 0
0
0
1
1
1
1
1
1 1
1
1
RAM
ROM
1 1 1 1 1
0000h
:
1FFFh
2000h
:
3FFFh
:
0000
RAM
8KByte
1FFF
2000
ROM
8KByte
I/O
4ports
1
1
1
1
1
1
1
1 1
1
1
1 1 1 0 0
FFF4h
1
1
1
1
1
1
1
1 1
1
1
1 1 1 1 1
FFFFh
I/O
:
3FFF
FFF4
FFFF
7
Direct Memory Access (DMA)
• Fungsi DMA
Address
Latches
AD0-AD15
Address Bus
ALE
Memory
Data Bus
µP
Data Bus
Control Bus
Control Bus
IOR, IOW, MEMW,
MEMR
HLDA HOLD
HLDA
HRQ
DMA
Controller
Control Bus
IOR, IOW, MEMW,
MEMR
DREQ
Peripheral
Device
DACK0
8
Bank Switching
• Memperbesar memory dengan switching
memory bank
A0 - A13
14
BANK 0
PORT
BANK 1
BANK 2
BS
BS
BS
BANK 7
BS
9
Extended Memory
• Alamat Memory Intel x86 di atas 1MByte
• Fungsi Extended Memory
10
Expanded Memory
• Memory tambahan melalui I/O Port
• Fungsi Expanded Memory
11
Virtual Memory
• Menggunakan
harddisk sebagai
memory data dan
program utama
• Fungsi Virtual
Memory
SELECTOR
OFFSET
LOGICAL
ADDRESS
SEGMENT
BASE
ADDRESSES
CONTROL AND
PROTECTION
BITS
DESCRIPTOR TABLE
PHYSICAL ADDRESS
12