source: avrstuff/EPRoxygen/at29c040.cpp@ 7d84448

#include "at29c040.h"

#include <stdio.h>
#include <unistd.h>


AT29C040::AT29C040()
        : Device()
{
}

void AT29C040::power()
{
        Device::write(CTRL, 0b10011111 | CTRLmask);
        Device::write(VOLT, 0b11001000 | VOLTmask);
        outb(port + 2, NONE);
}

void Device::shutdown()
{
        // All pins of the ROM are put either in high-Z, or 0V when it's not
        // possible
        Device::write(CTRL, 0b01100010);
        Device::write(VOLT, 0b01111111);
        outb(port + 2, NONE);
}

void AT29C040::read(const char* filename)
{
        if (!checkId()) {
                return;
        }
}

void AT29C040::write(const char* filename)
{
        if (!checkId()) {
                return;
        }
}

void AT29C040::erase(void)
{
        if (!checkId()) {
                return;
        }

        puts("Perfomring chip erase...");
}

bool AT29C040::checkId(void)
{
        // Chip enable
        Device::write(CTRL, CTRLmask | WE | OE | CE | A17);
                // Address bits low, WE = 1, CE = 0, OE = 1
                // TC and TD = 1
        Device::write(VOLT, VOLTmask);
                // D and A OE = 0
                // VPP config ?
                // TA, TB, TE, TF = ?

        wr16(0x5555, 0xAA);
        wr16(0xAAAA, 0x55);
        wr16(0x5555, 0x90);

        // clear DOE for reading
        Device::write(VOLT, DOE | VOLTmask);
        
        usleep(10000);

        // Read the result now
        Device::write(ADR0, 0x00);
                        usleep(1000);
        Device::write(ADR1, 0x00 ^ A13);
                        usleep(1000);
        Device::write(CTRL, WE | A17 | CTRLmask);
                        usleep(1000);
        uint8_t manufacturer = Device::read();


        Device::write(CTRL, CE | OE | WE | A17 | CTRLmask);
                        usleep(1000);
        Device::write(ADR0, 0x01);
                        usleep(1000);
        Device::write(CTRL, WE | A17 | CTRLmask);
                        usleep(1000);

        uint8_t product = Device::read();

        Device::write(CTRL, CE | WE | OE | A17 | CTRLmask);
                        usleep(1000);
        // re enable DOE, we are going to write again...
        Device::write(VOLT, VOLTmask);
                        usleep(1000);

        wr16(0x5555, 0xAA);
        wr16(0xAAAA, 0x55);
        wr16(0x5555, 0xF0);
        usleep(10000);

        // Chip disable - we're done !
        Device::write(CTRL, 0xFF | CTRLmask);
                        usleep(1000);
        
        bool ok = (manufacturer == 0x1F && product == 0xA4);

        if (!ok)
        {
                fprintf(stderr, "Chip ID %X:%X does not match expected %X:%X\n",
                        manufacturer, product, 0x1F, 0xA4);
        } else {
                fprintf(stderr, "AT29C040 detected successfully!\n");
        }

        return ok;
}