Low Level function - ISA Bus
[Ethernet to uC(microcontrollers)]

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Detailed Description

Definition of function's and parameter's to access RTL8019 chip, using ISA protocol

Author:

by Pinto de Castro(sirpdc@gmail.com)

 #include <isa_bus.h>

Address Bus Configuration
#define	ADDR_PORT   PORTA
	data port used for address bus
#define	ADDR_DDR   DDRA
	data direction for address bus
#define	ADDR_PINS   0b00011111
	port pins used by address bus( 1 indicate that the pin is used)
Data Bus Configuration
#define	DATA_PORT_L   PORTC
	port used for data bus
#define	DATA_DDR_L   DDRC
	data direction for data bus
#define	DATA_READ_L   PINC
	port used to read data
#define	DATA_PINS_L   0b11111111
	port pins used by data bus (1 indicate that the pin is used)
Control Bus Configuration
#define	CNTRL_PORT   PORTA
	port used for control bus
#define	CNTRL_DDR   DDRA
	data direction for control bus
#define	CNTRL_PINS   0b11100000
	port pins used by control bus (1 indicate that the pin is used)
#define	RESET_PIN   0b10000000
	port pin used by reset line (1 indicate that the pin is used)
#define	READ_PIN   0b00100000
	port pin used by read line (1 indicate that the pin is used)
#define	WRITE_PIN   0b01000000
	port pin used by write line (1 indicate that the pin is used)
Defines
#define	SetBits(_port_sss, _mask_sss)   _port_sss |= (_mask_sss)
	Set bit's positions that have 1 on mask.
#define	RstBits(_port_sss, _mask_sss)   _port_sss &= (~ (_mask_sss) )
	Reset bit's positions that have 0 on mask.
#define	WritePort(_port_sss, _mask_sss, _value_sss)
	Write a new value to port using mask: 1) put 0 on all the mask bits that are 0 2) put 1 on all the mask bits that are 1.
#define	nop()   asm volatile("nop\n\t"::)
	Insert a nop.
#define	WaitState()
	Insert a delay ~= 125ns.
Functions
void	rtl8019write (unsigned char data, unsigned char address)
	Writes byte to RTL8019 register.
unsigned char	rtl8019read (unsigned char address)
	Reads byte from RTL8019 register.
void	rtl8019SetupPorts (void)
	Sets up the ports used for communication with the RTL8019 NIC (data bus, address bus, read, write, and reset).

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Define Documentation

#define ADDR_DDR   DDRA

data direction for address bus Warning: Must be compatible with ADDR_PORT Definition at line 34 of file isa_bus.h. Referenced by rtl8019read(), rtl8019SetupPorts(), and rtl8019write().

#define ADDR_PINS   0b00011111

port pins used by address bus( 1 indicate that the pin is used) Definition at line 36 of file isa_bus.h. Referenced by rtl8019read(), rtl8019SetupPorts(), and rtl8019write().

#define ADDR_PORT   PORTA

data port used for address bus Definition at line 32 of file isa_bus.h. Referenced by rtl8019read(), and rtl8019write().

#define CNTRL_DDR   DDRA

data direction for control bus Warning: Must be compatible with CNTRL_PORT Definition at line 60 of file isa_bus.h. Referenced by rtl8019SetupPorts().

#define CNTRL_PINS   0b11100000

port pins used by control bus (1 indicate that the pin is used) Definition at line 62 of file isa_bus.h. Referenced by rtl8019SetupPorts().

#define CNTRL_PORT   PORTA

port used for control bus Definition at line 58 of file isa_bus.h. Referenced by main(), rtl8019read(), rtl8019SetupPorts(), and rtl8019write().

#define DATA_DDR_L   DDRC

data direction for data bus Warning: Must be compatible with DATA_PORT Definition at line 45 of file isa_bus.h. Referenced by rtl8019SetupPorts(), and rtl8019write().

#define DATA_PINS_L   0b11111111

port pins used by data bus (1 indicate that the pin is used) Definition at line 51 of file isa_bus.h. Referenced by rtl8019SetupPorts(), and rtl8019write().

#define DATA_PORT_L   PORTC

port used for data bus Definition at line 42 of file isa_bus.h. Referenced by rtl8019SetupPorts(), and rtl8019write().

#define DATA_READ_L   PINC

port used to read data Warning: Must be compatible with DATA_PORT Definition at line 48 of file isa_bus.h. Referenced by rtl8019read().

#define nop (   )     asm volatile("nop\n\t"::)

Insert a nop. Definition at line 105 of file isa_bus.h.

#define READ_PIN   0b00100000

port pin used by read line (1 indicate that the pin is used) Definition at line 66 of file isa_bus.h. Referenced by rtl8019read(), and rtl8019SetupPorts().

#define RESET_PIN   0b10000000

port pin used by reset line (1 indicate that the pin is used) Definition at line 64 of file isa_bus.h. Referenced by main(), and rtl8019SetupPorts().

#define RstBits (  _port_sss, _mask_sss   )     _port_sss &= (~ (_mask_sss) )

Reset bit's positions that have 0 on mask. Definition at line 92 of file isa_bus.h. Referenced by main(), rtl8019read(), rtl8019SetupPorts(), and rtl8019write().

#define SetBits (  _port_sss, _mask_sss   )     _port_sss |= (_mask_sss)

Set bit's positions that have 1 on mask. Definition at line 90 of file isa_bus.h. Referenced by main(), rtl8019read(), rtl8019SetupPorts(), and rtl8019write().

#define WaitState (   )

Value: { \ nop(); \ nop(); \ } Insert a delay ~= 125ns. Warning: Crystal values about 16MHz => PERIOD=62.5us => WaitState = 2*62.5us=125ns If you change the crystal pay attention to this Definition at line 113 of file isa_bus.h. Referenced by rtl8019read(), and rtl8019write().

#define WRITE_PIN   0b01000000

port pin used by write line (1 indicate that the pin is used) Definition at line 68 of file isa_bus.h. Referenced by rtl8019SetupPorts(), and rtl8019write().

#define WritePort (  _port_sss, _mask_sss, _value_sss   )

Value: RstBits( _port_sss, (_mask_sss) ); \ SetBits( _port_sss, ( (_mask_sss) & (_value_sss) ) ) Write a new value to port using mask: 1) put 0 on all the mask bits that are 0 2) put 1 on all the mask bits that are 1. Attention: i use the mask on seting bits just to be sure that i will not modify the rest of port content. Definition at line 100 of file isa_bus.h. Referenced by rtl8019read(), and rtl8019write().

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Function Documentation

unsigned char rtl8019read (  unsigned char  address  )

Reads byte from RTL8019 register. Parameters: address  address of register to read Warning: The data port is assumed to be already configured as input, and is left as an input port when done Definition at line 54 of file isa_bus.c. References ADDR_DDR, ADDR_PINS, ADDR_PORT, ASSERT, CNTRL_PORT, DATA_READ_L, READ_PIN, RstBits, SetBits, WaitState, and WritePort.

void rtl8019SetupPorts (  void   )

Sets up the ports used for communication with the RTL8019 NIC (data bus, address bus, read, write, and reset). Definition at line 84 of file isa_bus.c. References ADDR_DDR, ADDR_PINS, CNTRL_DDR, CNTRL_PINS, CNTRL_PORT, DATA_DDR_L, DATA_PINS_L, DATA_PORT_L, READ_PIN, RESET_PIN, RstBits, SetBits, and WRITE_PIN. Referenced by main().

void rtl8019write (  unsigned char  data, unsigned char  address )

Writes byte to RTL8019 register. Parameters: data  - byte to write to register address  - register address Warning: The data port is left in the input state with pullups enabled. Definition at line 20 of file isa_bus.c. References ADDR_DDR, ADDR_PINS, ADDR_PORT, ASSERT, CNTRL_PORT, DATA_DDR_L, DATA_PINS_L, DATA_PORT_L, RstBits, SetBits, WaitState, WRITE_PIN, and WritePort.

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