Matakuliah
Tahun
Versi
: H0194/ Aplikasi Mikroprosesor dan Interfacing
: 2005
: <<versi/revisi>>
Pertemuan 3 & 4
Interface Mikroprosesor
secara Paralel
1
Learning Outcomes
Pada akhir pertemuan ini, diharapkan mahasiswa
akan mampu :
• Menjelaskan interface mikroprosesor
secara parallel
2
Outline Materi
• Komunikasi Paralel
• Paralel Port Interface
• Programmable Peripheral Interface
3
Komunikasi Paralel
• Pengertian komunikasi
paralel
• Metode komunikasi
paralel
DATA
(a)
STB
DATA
(b)
STB
ACK
DATA
(c)
STB
ACK
DATA
(d)
4
Paralel Port Interface
• Pengenalan Paralel Port
• Mode Operasi pada Standard Paralel Port:
– Compatibility Mode
– Nibble Mode
– Byte Mode
– EPP Mode
– ECP Mode
5
Paralel Port Interface
• Standard Paralel
Port (SPP)
• Transfer Rate:
50 – 150 KB/s
Microcomputer
Printer
STROBE
DATA[7:0]
ACKNLG
BUSY
PE
SLCT
AUTO FEED XT
ERROR
INIT
SLCT IN
GND
6
Paralel Port Interface
• SPP Centronics Handshake
• SPP Port Address
• SPP Software Registers
7
Paralel Port Interface
• Enhanced
Paralel Port
(EPP)
• Transfer
Rate:
500KB/S –
2MB/s
8
Paralel Port Interface
• EPP Handshake
–
–
–
–
Data write cycle
Address write cycle
Data read cycle
Address read cycle
• EPP Software Registers
• http://www.beyondlogic.org/epp/epp.htm
9
Paralel Port Interface
• Extended
Capabilities
Port (ECP)
• DMA
Enabled
• FIFO
• Run Length
Encoding
(RLE)
10
Paralel Port Interface
• ECP Handshake
–
–
–
–
ECP Forward Data Cycle
ECP Forward Command Cycle
ECP Reverse Data Cycle
ECP Reverse Command Cycle
• ECP Run Length Encoding (RLE)
• ECP Software Registers
– ECP Extended Control Register (ECR)
– ECP Configuration Register A
– ECP Configuration Register B
• http://www.beyondlogic.org/ecp/ecp.htm
11
Programmable Peripheral
Interface
• PPI 8255
• Programmable I/O Device
• Spesifikasi:
– Memiliki 3 Port 8-bit
• Port A
• Port B
• Port C
– Memiliki 3 Mode Operasi
• Mode 0 (Basic I/O)
• Mode 1 (Strobed I/O)
• Mode 3 (Bidirectional I/O)
12
Programmable Peripheral
Interface
• Blok Diagram
– Group A
• Port A[7:0]
• Port C[7:4]
– Group B
• Port B[7:0]
• Port C[3:0]
13
Programmable Peripheral
Interface
• Alamat dan control pada PPI 8255
14
Programmable Peripheral
Interface
• Control Word untuk mode operasi
D7
D6
D5
D4
D3
D2
D1
D0
Control Group B
Port C ( low order 4 bit )
1 = input
0 = output
Port B
1 = Input
0 = Output
Select Mode
0 = mode 0
1 = mode 1
Control Group A
Port C ( high order 4 bit )
1 = input
0 = output
Port A
1 = Input
0 = Output
Select Mode
00 = mode 0
01 = mode 1
10 = mode 2
1x = mode 3
Mode flag setting
1 = enable
15
Programmable Peripheral
Interface
• Control Word untuk set/reset port C
16
Programmable Peripheral
Interface
• PPI 8255 Mode 0:
• Tidak ada fasilitas handshaking
• Masing-masing port hanya dapat
dioperasikan sebagai input atau output
saja
• Tersedia latch untuk output
17
Programmable Peripheral
Interface
• PPI 8255 Mode 1 (Strobed Input):
Sebagian pin Port C digunakan untuk STB, IBF, dan INTR
18
Programmable Peripheral
Interface
• PPI 8255 Mode 1 (Strobed Output):
Sebagian pin Port C digunakan untuk STB, IBF, dan INTR
19
Programmable Peripheral
Interface
• PPI 8255 Mode 2 (Strobed Bidirectional):
WR
OBF
INTR
ACK
STB
IBF
INTR
RD
Data Bus
RD
WR
20