8085 HOW-TO GUIDE Interfacing 8251 with 8085

Size: px

Start display at page:

Download "8085 HOW-TO GUIDE Interfacing 8251 with 8085"

Tracey Scott
5 years ago
Views:

1 8085 HOW-TO GUIDE Interfacing 8251 with 8085

2 Contents at a Glance 8085 Trainer Board (USART)... 3 Interfacing 8251 with Pin Assignment with Circuit Diagram to Interface 8251 with Assembly program to interface 8251 with

3 8085 Trainer Board PS-TRAINER-8085 microprocessor trainer kit is proposed to smooth the progress of learning and developing designs of microprocessor from Intel. It has the Facility to connect PC s 101/104 Keyboard, to enter user programs in Assembly languages. User verifies the programs through LCD or PC. User friendly Firmware confirms facilitating the beginners learns operations of a microprocessor quickly (USART) The RS232C interface of PS-TIMER & USART comprises of the universal synchronous/asynchronous receiver/transmitter 8251 (USART), RS232C driver max 232. The 8251A is used here as a peripheral device for serial communication and is programmed by the CPU to operate using virtually any serial data transmission technique. The USART accepts data characters from the CPU in parallel

4 format and then converts them into a continuous serial data stream for transmission. Simultaneously, it can receive serial data streams and convert them into parallel data characters for the CPU. The CPU can read the status of the USART at any time. These include data transmission errors and control signals. Interfacing 8251 with 8085 Microprocessor don t have the direct serial communications, so to communicate the data serially to a device we need a driver to send a character serially, here we use is a driver which converts the parallel data to a serial data the pin detail and control pins are given so according to that we can develop the hardware

8255 DATA LINES CONTROL L LINES Pin Assignment with 8051 8085 8255 8255 PIN DIAGRAM 13 A1 29 RD 30 WR 24 CLK 3 RST From

5 8255 DATA LINES CONTROL L LINES Pin Assignment with PIN DIAGRAM 13 A1 29 RD 30 WR 24 CLK 3 RST From decoder CS 12 D0 13 D1 14 D2 15 D3 16 D4 17 D5 18 D6 19 D7 VCC Address line and data lines are Decoded GND 20 7 using Latch

6 GND 4 VCC 15 6 GND V- VCC Circuit Diagram to Interface 8251 with 8051 VCC C1 0.1UF VCC C8 P1 D7 D6 D5 D4 D3 D2 D1 D0 PCLK RST WR RD U D7 RTS 6 D6 CTS 5 D5 2 D4 1 D3 28 D2 27 D1 DSR 20 D0 21 CLK RXRDY 10 RESET 13 WR 11 RD 12 CS TXD 15 C/D RXD TXC 24 RXC T1IN R1OUT OUT2 U2 9 R1OUT12 R2OUT T1IN 11 R1OUT 10 T1IN 7 T2IN T2OUT MAX232 C6 22MF T1OUT R2IN R1IN V+ C2- C2+ C1- C VCC C3 2 22MFD 5 C4 4 22MFD 3 C5 1 22MFD COM MFD

7 Assembly program to interface 8251 with 8085 *************************************************************************************** Title : Program to transmit a character from 8251 to the HyperTerminal using 8085 *************************************************************************************** ADDRESS OPCODE NEMONICS E B6 MVI A,B D3 23 OUT E 40 MVI A,B D3 22 OUT E 01 MVI A,01 910A D3 22 OUT C 0E 05 REPET : MVI C,05 910E DB 01 CHECK: IN E6 04 ANI CA 0E 91 JZ CHECK START : LXI H,LOOK UP C MVI B,0C 911A 7E REPT1: MOV A,M 911B D3 00 OUT D LXI D, DELAY: NOP B DCX D B MOV A,E 9123 B2 ORA D 9124 C JNZ DELAY INX H DCR B 9129 C2 1A 91 JNZ REPT1 912C C JMP START 912F FE 3F CPI 3F 9131 C2 0C 91 JNZ REPET D DCR C 9135 C2 0E 91 JNZ CHECK 9138 CF RST 1

8 LOOK UP TABLE: ADDRESS DATA H,45H,4CH,4CH FH,2DH,38H,30H (HELLO-8085) H,35H,0AH,0DH 920C END

9 Did you enjoy the read? Pantech solutions creates information packed technical documents like this one every month. And our website is a rich and trusted resource used by a vibrant online community of more than 1,00,000 members from organization of all shapes and sizes.

10 What do we sell? Our products range from Various Microcontroller development boards, DSP Boards, FPGA/CPLD boards, Communication Kits, Power electronics, Basic electronics, Robotics, Sensors, Electronic components and much more. Our goal is to make finding the parts and information you need easier and affordable so you can create awesome projects and training from Basic to Cutting edge technology.

ARM HOW-TO GUIDE Interfacing GPS with LPC2148 ARM

ARM HOW-TO GUIDE Interfacing GPS with LPC2148 ARM Contents at a Glance ARM7 LPC2148 Primer Board... 3 GPS (Global Positioning Systems)... 3 Interfacing GPS... 4 Interfacing GPS with LPC2148... 5 Pin Assignment