How to Use Timer-0 in AT89C1051 (Split Mode)

-
The following code demonstrate, how to use timer-0 in split mode. In this mode TL0 and TH0 both are incremented by 1 on each clock cycle. Both timer-0 registers are incremented independently. Timer flag TF0 is generate when TL0 count reaches 256 and TF1 is generated when TH0 count reaches 256. The code is written in Keil uVision2 IDE and simulation is done with Proteus 8.0. At the end of code, you can find complete project files for download.

Code Using Keil uVision2

#include <REG51.H>
#include <stdio.h>
// proto-types
void ConfigTimerSplitMode(void);
void MonitorTimer1OverflowFlag(void);
void Delayms(unsigned int x_time);
// pin labling
sbit CLK0 = P1^0;
sbit CLK1 = P1^1;
sbit TF0_STATUS = P3^0;
sbit TF1_STATUS = P3^1;
void main(void)
{
// make as output
CLK0 = 0;
CLK1 = 0;
TF0_STATUS = 0;
TF1_STATUS = 0;
// config timer in split mode
ConfigTimerSplitMode();
while(1)
{
// flag status
TF0_STATUS = TF0;
if(TF0 == 1)
{
CLK0 = ~CLK0;
TF0 = 0;
TL0 = 0;
}
TF1_STATUS = TF1;
if(TF1 == 1)
{
CLK1 = ~CLK1;
TF1 = 0;
TH0 = 50;
}
}
}
void ConfigTimerSplitMode(void)
{
// master clock is 12MHz
// timer clock is 1/12th => 1MHz
// clear all registers
TL0 = 0;
TH0 = 50;
// set timer-0, mode-3 (8-bit split)
// set timer-1 disable
TMOD = 0x33;
// start timer-0
TR0 = 1;
// start timer-1
TR1 = 1;
}
void Delayms(unsigned int x_time)
{
unsigned int x,y;
for(x=0;x<x_time;x++)
for(y=0;y<122;y++);
}

Download Files

For download Keil project and Proteus 8.0 simulation files, click here.

Comments

Post a Comment

Popular posts from this blog

How to Program Parallel Slave Port (PSP) in PIC16F877A

-
Image
The following code demonstrate how to use parallel slave port module. The controller offers a mechanism by which an 8-bit parallel bidirectional data transfer can be achieved between a PIC16F877A and other PSP supporting devices. The PIC16F877A's Port-D and Port-E are used in this data transfer. For this data transfer, Port-D is configured as a parallel slave port (PSP) by setting bit-4 of TRISE Register. The pins of Port-E function as control pins for data transfer. The code is written in “mikroC PRO for PIC v.6.6.3” IDE and simulation is done with Proteus 8.0 SP0. At the end of code, you can find complete project files for download. UUT Code in mikroC // function proto-type void PSP_Setting(void); void main(void) { // portb as input port TRISB = 0xFF; // portc as output port TRISC = 0x00; // portc init to 0x00 PORTC = 0x00; PSP_Setting(); while(1) { // write request to PSP if(TRISE.IBF == 1) { PORTC = PORTD; // auto clear
Read more

How to Program Interrupts in PIC16F877A

-
Image
There are 15 interrupts available in PIC16F877A controller. I will try to demonstrate individual interrupt so that you can easily understand. The list is the following. 1. External Interrupt 2. RB Port Change Interrupt 3. Timer 0 Interrupt 4. Timer 1 Interrupt 5. Parallel Slave Port Read/Write Interrupt 6. A/D Converter Interrupt 7. USART Receive Interrupt 8. USART Transmit Interrupt 9. SPI (Slave) Interrupt 9. Synchronous Serial Port Interrupt 10. CCP1 (Capture, Compare, PWM) Interrupt 11. CCP2  (Capture, Compare, PWM) Interrupt 12. TMR2 to PR2 Match Interrupt 13. Comparator Interrupt 14. EEPROM Write Operation Interrupt 15. Bus Collision Interrupt 1. External Interrupt (RB0) The following code demonstrates how to use external interrupt (RB0). A push button is connected to RB0/INT, when push button is pressed a high to low signal is generated. As in option register external interrupt is configured on falling edge so interrupt is generated and interrupt serv
Read more

How to Program SPI in PIC16F877A (Slave Mode)

-
Image
The following code demonstrate, how to write a program to use SPI (serial peripheral interface) in slave mode. Timer-2 is used to provide clock to SPI module, so you can not use Timer-2 for any other purpose if you are using SPI module. One controller is running in master SPI mode, while the other is running in slave mode. Master send a up counter value to the slave controller. The slave controller receive data and write received data to PORTD. SPI has the four wire interface: SCK (PORTC.3) Serial clock output from master and input to slave [SCK] SDI (PORTC.4) Serial data input to master and output from slave [SDO] SDO (PORTC.5) Serial data output from master and input to slave [SDI] SS (PORTA.5) Slave select active low output from master and input to slave [SS] The SPI data is monitored on SPI debuger and also all signals are displayed on oscilloscope. The code is written in “mikroC PRO for PIC v.5.6.1” IDE and simulation is done with Proteus 8.0 SP0. At the end of code, you
Read more