//-----------------------------------------------------------------------------
// F33x_UART_STDIO.c
//-----------------------------------------------------------------------------
// Copyright 2006 Silicon Laboratories, Inc.
// http://www.silabs.com
//
// Program Description:
//
// This program demonstrates how to configure the C8051F330 to use routines
// in STDIO.h to write to and read from the UART interface. The program
// reads a character using the STDIO routine getkey(), outputs that character
// to the screen, and then outputs the ASCII hex value of that character.
//
//
// How To Test:
//
// 1) Ensure that jumpers are placed on J12 of the C8051F330 target board
// that connect P0.4 to the TX signal, and P0.5 to the RX field.
// 2) Ensure that the serial cable is connected to the RS232 connector
// on the target board.
// 3) Specify the target baudrate in the constant <BAUDRATE>.
// 4) Open Hyperterminal, or a similar program, and connect to the target
// board's serial port.
// 5) Download and execute code to an 'F330 target board.
//
//
// FID: 33X000035
// Target: C8051F33x
// Tool chain: Keil C51 7.50 / Keil EVAL C51
// Command Line: None
//
// Release 1.0
// -Initial Revision (PD)
// -16 AUG 2006
//
//-----------------------------------------------------------------------------
// Includes
//-----------------------------------------------------------------------------
#include <c8051f330.h> // SFR declarations
#include <stdio.h>
//-----------------------------------------------------------------------------
// Global CONSTANTS
//-----------------------------------------------------------------------------
#define SYSCLK 24500000 // SYSCLK frequency in Hz
#define BAUDRATE 9600 // Baud rate of UART in bps
//-----------------------------------------------------------------------------
// Function PROTOTYPES
//-----------------------------------------------------------------------------
void SYSCLK_Init (void);
void UART0_Init (void);
void PORT_Init (void);
void Timer2_Init (int);
//-----------------------------------------------------------------------------
// MAIN Routine
//-----------------------------------------------------------------------------
void main (void)
{
unsigned char inputcharacter; // Used to store character from UART
PCA0MD &= ~0x40; // WDTE = 0 (clear watchdog timer
// enable)
PORT_Init(); // Initialize Port I/O
SYSCLK_Init (); // Initialize Oscillator
UART0_Init();
while (1)
{
printf ("\nEnter character: ");
inputcharacter = getchar ();
printf ("\nCharacter entered : %c",inputcharacter);
printf ("\n Value in Hex: %bx",inputcharacter);
}
}
//-----------------------------------------------------------------------------
// Initialization Subroutines
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
// PORT_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configure the Crossbar and GPIO ports.
//
// P0.4 digital push-pull UART TX
// P0.5 digital open-drain UART RX
//
//-----------------------------------------------------------------------------
void PORT_Init (void)
{
P0MDOUT |= 0x10; // Enable UTX as push-pull output
XBR0 = 0x01; // Enable UART on P0.4(TX) and P0.5(RX)
XBR1 = 0x40; // Enable crossbar and weak pull-ups
}
//-----------------------------------------------------------------------------
// SYSCLK_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// This routine initializes the system clock to use the internal oscillator
// at its maximum frequency.
// Also enables the Missing Clock Detector.
//-----------------------------------------------------------------------------
void SYSCLK_Init (void)
{
OSCICN |= 0x03; // Configure internal oscillator for
// its maximum frequency
RSTSRC = 0x04; // Enable missing clock detector
}
//-----------------------------------------------------------------------------
// UART0_Init
//-----------------------------------------------------------------------------
//
// Return Value : None
// Parameters : None
//
// Configure the UART0 using Timer1, for <BAUDRATE> and 8-N-1.
//-----------------------------------------------------------------------------
void UART0_Init (void)
{
SCON0 = 0x10; // SCON0: 8-bit variable bit rate
// level of STOP bit is ignored
// RX enabled
// ninth bits are zeros
// clear RI0 and TI0 bits
if (SYSCLK/BAUDRATE/2/256 < 1) {
TH1 = -(SYSCLK/BAUDRATE/2);
CKCON &= ~0x0B; // T1M = 1; SCA1:0 = xx
CKCON |= 0x08;
} else if (SYSCLK/BAUDRATE/2/256 < 4) {
TH1 = -(SYSCLK/BAUDRATE/2/4);
CKCON &= ~0x0B; // T1M = 0; SCA1:0 = 01
CKCON |= 0x01;
} else if (SYSCLK/BAUDRATE/2/256 < 12) {
TH1 = -(SYSCLK/BAUDRATE/2/12);
CKCON &= ~0x0B; // T1M = 0; SCA1:0 = 00
} else {
TH1 = -(SYSCLK/BAUDRATE/2/48);
CKCON &= ~0x0B; // T1M = 0; SCA1:0 = 10
CKCON |= 0x02;
}
TL1 = TH1; // Init Timer1
TMOD &= ~0xf0; // TMOD: timer 1 in 8-bit autoreload
TMOD |= 0x20;
TR1 = 1; // START Timer1
TI0 = 1; // Indicate TX0 ready
}
//-----------------------------------------------------------------------------
// End Of File
//-----------------------------------------------------------------------------