The Microprocessor

APPENDIX DAM0 Header Files

This chapter contains two header files for the abstract microcontroller AM0 used in chapters 17 to 19: am0_regs.h, which defines the memory-mapped peripheral registers, and am0.h, which defines application programming interface (API) for accessing the peripherals.

D.1 REGISTER HEADER FILE

A microcontroller vendor typically provides a platform header file that contains definitions of all the memory-mapped registers. Since we have defined the AM0 peripherals, let us create its header file am0_regs.h.

Quite often, a header file also includes definitions of individual bits and their positions within a register. We will omit these from am0_regs.h for simplicity.

#ifndef AM0_REGS_H
#define AM0_REGS_H
 
 
#define IOREG(addr) (*(volatile long *)(addr))
 
 
#define GPIO_DAT  IOREG(0x40001000)  // GPIO data register
#define GPIO_DIR  IOREG(0x40001004)  // GPIO direction register
#define GPIO_INT  IOREG(0x40001008)  // GPIO interrupt enable register
 
 
#define TIMER_CSR IOREG(0x40002000)  // Timer control and status register
#define TIMER_RVR IOREG(0x40002004)  // Timer reload value register
#define TIMER_CVR IOREG(0x40002008)  // Timer current value register
 
 
#define ADC_DAT   IOREG(0x40003000)  // ADC data register
 
 
#define DAC_DAT   IOREG(0x40004000)  // DAC data register
 
 
#define UART_CSR  IOREG(0x40005000)  // UART control and status register
#define UART_RDR  IOREG(0x40005004)  // UART receive data register
#define UART_TDR  IOREG(0x40005008)  // UART transmit data register
 
 
#define ...