monitor.c File Reference

Detailed Description

You can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version.

This program works with the connection scheme used in Atmels "STK200 Starter Kit". The connection allows to program the AVR with Uros Platise `uisp' in `-dstk200' mode.

Bugs: For me this work only if Parallell port in EPP mode. May be ECP mode also work?

2002 June Jörgen Birkler (birkler@yahoo.com)

Updated code to work with GCC 3.2.
Renamed some of the communications functions to better reflect their origin 'Monitor_'.
Added AT90S8535 as target.

2003 April Jörgen Birkler (birkler@yahoo.com)

Using GCC 3.3
Updates to host-target protocol.
More comments to monitor trap loop
Trap loop now easier to configure to different hardware and interrupts
8 Hardware breakpoints

2003 November Jörgen Birkler (birkler@yahoo.com)

Reworked the protocol completetly, now using SPI
- Hardware slave receives clock; no missed bits
- MISO,MOSI,SCK to HOST. SS tied to MOSI.
- RX bit is piggy backed in the SPI_SCK just before SS goes high
- Uses SPI interrupt for assembler stepping
Rewrote the PC monitor using C++ and threads

Defines

#define AVR_MONITOR_TARGET
#define MONITOR_INTERRUPT
#define SPI_ENABLE()
#define SPI_ENABLE_INT()
#define SPI_DISABLE_INT()
#define SPI_ENABLE_MASTER()
#define SPI_WAIT_UNTIL_A_SLAVE()
#define SPI_DISABLE()
#define SPI_SLAVE_INIT()
#define D_(x)
#define SPI_TIMEOUT_COUNT
#define AVR_MONITOR_IS_RX_SYNC(val)
#define hi8(x)
#define lo8(x)
#define AVR_MONITOR_HW_BREAKPOINTS
#define monitor_send_address(lo, hi)
#define JOIN(X, Y)
#define DO_JOIN(X, Y)
#define DO_JOIN2(X, Y)
#define STATIC_ASSERT_(_pred)

Functions

void monitor (void)
void Monitor_InitComm (void)
int16_t SPI_Slave_Transfer (uint8_t tx_byte)
void Monitor_SendChar (uint8_t data)
uint8_t Monitor_ReceiveByte (void)
void gdb_break (void)
void monitor_enter (void)
void MONITOR_INTERRUPT (void)
void monitor_send_byte (uint8_t b)
STATIC_ASSERT_ (sizeof(avr_monitor_data.regs)==AVR_MONITOR_REGS_SIZE)
STATIC_ASSERT_ (offsetof(avr_monitor_data_t, hw_bp_flags)==AVR_MONITOR_BP_FLAGS_OFFSET)
STATIC_ASSERT_ (offsetof(avr_monitor_data_t, continue_cmd)==AVR_MONITOR_CONTINUE_CMD_OFFSET)
STATIC_ASSERT_ (offsetof(avr_monitor_data_t, breakpoint)==AVR_MONITOR_BREAKPOINTS_OFFSET)
STATIC_ASSERT_ (sizeof(avr_monitor_data.breakpoint)==AVR_MONITOR_BREAKPOINTS_SIZE)
STATIC_ASSERT_ (offsetof(avr_monitor_data_t, stack)==AVR_MONITOR_STACK_OFFSET)
STATIC_ASSERT_ (sizeof(avr_monitor_data)==AVR_MONITOR_DATA_SIZE)
STATIC_ASSERT_ (AVR_MONITOR_DATA_SIZE==0x3F)
STATIC_ASSERT_ (AVR_MONITOR_SIZEOF_DATA_INFO==sizeof(avr_monitor_data_info_t))

Variables

volatile avr_monitor_data_t avr_monitor_data
const avr_monitor_data_info_t
PROGMEM monitor_info

Define Documentation

#define MONITOR_INTERRUPT

Todo:
More hardware configurations
jbirkler:Add Timer1 and Timer2 to supported interrupts

#define SPI_SLAVE_INIT ( )

Enable for slave MISO is output, everything else is input with pull-up enabled
Author:
Jorgen Birkler (birkler@yahoo.com)

#define AVR_MONITOR_IS_RX_SYNC ( val )

Sync host to target communication with a trailing 10 ones followed by 4 zeros.

Author:
Jorgen Birkler (birkler@yahoo.com)
00111111111100xxxxxxxx

Function Documentation

void monitor ( void )

int16_t SPI_Slave_Transfer ( uint8_t tx_byte ) [static]

Slave transmit Wait until the previous tranfer is complete and writes to the data register

Author:
Jorgen Birkler (birkler@yahoo.com)
Its seems that the SPIF bit in SPSR is set after 8 bits have been shifted into the shift register not when SS goes high. The datasheet doesn't explicitly say but when reading the text you can get the impression that SS low-high triggers the SPIF bit, this is not so. The hardware seems also to be very confused if there is not exactly 8 bits. 7 bits = nothing, 9 bits = garbage.
By enabling clock phase CPHA (after testing I found that this works in mode 1 but not in mode 0) it is possible to piggy pack a bit from the host to the target (remember that MOSI is controlling SS; MOSI cannot be used) by letting the SPI_SCK be either 1 or 0 when SS goes high.
Bytes in the piggy back bit is synced so that the target can determine when it received a complete byte, see AVR_MONITOR_IS_RX_SYNC.

Parameters:

tx_byte Byte to send

Return values:

-1 no byte recieved

0..255 byte recieved

void Monitor_SendChar ( uint8_t data )

High level routine for sending one byte of data. Blocks until the host is ready to receive.

uint8_t Monitor_ReceiveByte ( void ) [static]

High level routine for receiving one byte of data. Blocks until the host is ready to send.

void MONITOR_INTERRUPT ( void )