/* * isp.c - part of USBasp * * Autor..........: Thomas Fischl * Description....: Provides functions for communication/programming * over ISP interface * Licence........: GNU GPL v2 (see Readme.txt) * Creation Date..: 2005-02-23 * Last change....: 2010-01-19 */ #include #include "isp.h" #include "clock.h" #include "usbasp.h" #define spiHWdisable() SPCR = 0 uchar sck_sw_delay; uchar sck_spcr; uchar sck_spsr; uchar isp_hiaddr; void spiHWenable() { SPCR = sck_spcr; SPSR = sck_spsr; } void ispSetSCKOption(uchar option) { if (option == USBASP_ISP_SCK_AUTO) option = USBASP_ISP_SCK_375; if (option >= USBASP_ISP_SCK_93_75) { ispTransmit = ispTransmit_hw; sck_spsr = 0; sck_sw_delay = 1; /* force RST#/SCK pulse for 320us */ switch (option) { case USBASP_ISP_SCK_1500: /* enable SPI, master, 1.5MHz, XTAL/8 */ sck_spcr = (1 << SPE) | (1 << MSTR) | (1 << SPR0); sck_spsr = (1 << SPI2X); case USBASP_ISP_SCK_750: /* enable SPI, master, 750kHz, XTAL/16 */ sck_spcr = (1 << SPE) | (1 << MSTR) | (1 << SPR0); break; case USBASP_ISP_SCK_375: default: /* enable SPI, master, 375kHz, XTAL/32 (default) */ sck_spcr = (1 << SPE) | (1 << MSTR) | (1 << SPR1); sck_spsr = (1 << SPI2X); break; case USBASP_ISP_SCK_187_5: /* enable SPI, master, 187.5kHz XTAL/64 */ sck_spcr = (1 << SPE) | (1 << MSTR) | (1 << SPR1); break; case USBASP_ISP_SCK_93_75: /* enable SPI, master, 93.75kHz XTAL/128 */ sck_spcr = (1 << SPE) | (1 << MSTR) | (1 << SPR1) | (1 << SPR0); break; } } else { ispTransmit = ispTransmit_sw; switch (option) { case USBASP_ISP_SCK_32: sck_sw_delay = 3; break; case USBASP_ISP_SCK_16: sck_sw_delay = 6; break; case USBASP_ISP_SCK_8: sck_sw_delay = 12; break; case USBASP_ISP_SCK_4: sck_sw_delay = 24; break; case USBASP_ISP_SCK_2: sck_sw_delay = 48; break; case USBASP_ISP_SCK_1: sck_sw_delay = 96; break; case USBASP_ISP_SCK_0_5: sck_sw_delay = 192; break; } } } void ispDelay() { uint8_t starttime = TIMERVALUE; while ((uint8_t) (TIMERVALUE - starttime) < sck_sw_delay) { } } void ispConnect() { /* all ISP pins are inputs before */ /* now set output pins */ ISP_DDR |= (1 << ISP_RST) | (1 << ISP_SCK) | (1 << ISP_MOSI); /* reset device */ ISP_OUT &= ~(1 << ISP_RST); /* RST low */ ISP_OUT &= ~(1 << ISP_SCK); /* SCK low */ /* positive reset pulse > 2 SCK (target) */ ispDelay(); ISP_OUT |= (1 << ISP_RST); /* RST high */ ispDelay(); ISP_OUT &= ~(1 << ISP_RST); /* RST low */ if (ispTransmit == ispTransmit_hw) { spiHWenable(); } /* Initial extended address value */ isp_hiaddr = 0; } void ispDisconnect() { /* set all ISP pins inputs */ ISP_DDR &= ~((1 << ISP_RST) | (1 << ISP_SCK) | (1 << ISP_MOSI)); /* switch pullups off */ ISP_OUT &= ~((1 << ISP_RST) | (1 << ISP_SCK) | (1 << ISP_MOSI)); /* disable hardware SPI */ spiHWdisable(); } uchar ispTransmit_sw(uchar send_byte) { uchar rec_byte = 0; uchar i; for (i = 0; i < 8; i++) { /* set MSB to MOSI-pin */ if ((send_byte & 0x80) != 0) { ISP_OUT |= (1 << ISP_MOSI); /* MOSI high */ } else { ISP_OUT &= ~(1 << ISP_MOSI); /* MOSI low */ } /* shift to next bit */ send_byte = send_byte << 1; /* receive data */ rec_byte = rec_byte << 1; if ((ISP_IN & (1 << ISP_MISO)) != 0) { rec_byte++; } /* pulse SCK */ ISP_OUT |= (1 << ISP_SCK); /* SCK high */ ispDelay(); ISP_OUT &= ~(1 << ISP_SCK); /* SCK low */ ispDelay(); } return rec_byte; } uchar ispTransmit_hw(uchar send_byte) { SPDR = send_byte; while (!(SPSR & (1 << SPIF))) ; return SPDR; } uchar ispEnterProgrammingMode() { uchar check; uchar count = 32; while (count--) { ispTransmit(0xAC); ispTransmit(0x53); check = ispTransmit(0); ispTransmit(0); if (check == 0x53) { return 0; } spiHWdisable(); /* pulse RST */ ispDelay(); ISP_OUT |= (1 << ISP_RST); /* RST high */ ispDelay(); ISP_OUT &= ~(1 << ISP_RST); /* RST low */ ispDelay(); if (ispTransmit == ispTransmit_hw) { spiHWenable(); } } return 1; /* error: device dosn't answer */ } static void ispUpdateExtended(unsigned long address) { uchar curr_hiaddr; curr_hiaddr = (address >> 17); /* check if extended address byte is changed */ if(isp_hiaddr != curr_hiaddr) { isp_hiaddr = curr_hiaddr; /* Load Extended Address byte */ ispTransmit(0x4D); ispTransmit(0x00); ispTransmit(isp_hiaddr); ispTransmit(0x00); } } uchar ispReadFlash(unsigned long address) { ispUpdateExtended(address); ispTransmit(0x20 | ((address & 1) << 3)); ispTransmit(address >> 9); ispTransmit(address >> 1); return ispTransmit(0); } uchar ispWriteFlash(unsigned long address, uchar data, uchar pollmode) { /* 0xFF is value after chip erase, so skip programming if (data == 0xFF) { return 0; } */ ispUpdateExtended(address); ispTransmit(0x40 | ((address & 1) << 3)); ispTransmit(address >> 9); ispTransmit(address >> 1); ispTransmit(data); if (pollmode == 0) return 0; if (data == 0x7F) { clockWait(15); /* wait 4,8 ms */ return 0; } else { /* polling flash */ uchar retries = 30; uint8_t starttime = TIMERVALUE; while (retries != 0) { if (ispReadFlash(address) != 0x7F) { return 0; }; if ((uint8_t) (TIMERVALUE - starttime) > CLOCK_T_320us) { starttime = TIMERVALUE; retries--; } } return 1; /* error */ } } uchar ispFlushPage(unsigned long address, uchar pollvalue) { ispUpdateExtended(address); ispTransmit(0x4C); ispTransmit(address >> 9); ispTransmit(address >> 1); ispTransmit(0); if (pollvalue == 0xFF) { clockWait(15); return 0; } else { /* polling flash */ uchar retries = 30; uint8_t starttime = TIMERVALUE; while (retries != 0) { if (ispReadFlash(address) != 0xFF) { return 0; }; if ((uint8_t) (TIMERVALUE - starttime) > CLOCK_T_320us) { starttime = TIMERVALUE; retries--; } } return 1; /* error */ } } uchar ispReadEEPROM(unsigned int address) { ispTransmit(0xA0); ispTransmit(address >> 8); ispTransmit(address); return ispTransmit(0); } uchar ispWriteEEPROM(unsigned int address, uchar data) { ispTransmit(0xC0); ispTransmit(address >> 8); ispTransmit(address); ispTransmit(data); clockWait(30); // wait 9,6 ms return 0; }