I'm trying to handle AT45DB161D SPI flash memory using the following code and could not read status/ID info correctly.
The test code read only status register and device ID (read/write data block is not implemented yet).
The read value from this test code resulted 0xFF, not expected value.
However, the same code worked as expected with FEZ Domino.
As I don't have oscilloscope, I could not narrow down the issue. Is there any advice for more investigation?
Test environments:
- Firmware: 4.1.0.3
- Host PC OS: Windows 7
- Change clock rate lower/higher than 1000Khz
- Change SPI mode to 3 (Clock_IdleState = true, Clock_Edge = false)
- Specify ChipSelect_Port in "SPI.Configuration". AS this resulted NG even with FEZ Domino, it seems AT45DB161D require CS active during command send and result acquisition period
- Insert wait (1ms) between CS active and start transaction
- Change jumper wire of SCK
- Power supply from external power jack
using System.Threading;
using Microsoft.SPOT;
using Microsoft.SPOT.Hardware;
using SecretLabs.NETMF.Hardware.Netduino;
/* -------------------------------------------
* Pin assignment Netduino <--> AT45DB161D
* CS D8 -- 4 Pull-up with 10k ohm R
* RESET D9 -- 3 Pull-down with 10k ohm R
* MOSI D11 -- 1
* MISO D12 -- 8
* SCK D13 -- 2
--------------------------------------------*/
namespace NetSpiFlash
{
public class Program
{
public static void Main()
{
OutputPort csPin = new OutputPort(Pins.GPIO_PIN_D8, true);
OutputPort resetPin = new OutputPort(Pins.GPIO_PIN_D9, true);
SPI.Configuration config = new SPI.Configuration(
Cpu.Pin.GPIO_NONE, // ChipSelect_Port. Not connected to the device
false, // ChipSelect_ActiveState : active low
0, // ChipSelect_SetupTime
0, // ChipSelect_HoldTime
false, // Clock_IdleState : the idle state of the clock is low
true, // Data is sampled on the SPI clock riging edge (Mode 0)
1000, // Clock_Rate in KHz
SPI.SPI_module.SPI1 // SPI_mod : D11 MOSI, D12 MISO, D13 SCK
);
SPI spi1 = new SPI(config);
AT45DB161D SpiFlash = new AT45DB161D(spi1, csPin, resetPin);
byte status;
while (true)
{
status = SpiFlash.ReadStatusRegister();
Debug.Print("Status Reg:" + status.ToString());
SpiFlash.ReadManufacturerAndDeviceID();
Debug.Print("Manufacturer ID:" + SpiFlash.Manufacturer.ToString());
Debug.Print("Device ID:" + SpiFlash.Device[0].ToString());
Thread.Sleep(1000);
}
}
}
public class AT45DB161D
{
// AT45DB161D_Commands
private const byte STATUS_REGISTER_READ = 0xD7;
private const byte READ_MANUFACTURER_AND_DEVICE_ID = 0x9F;
// Chip Select value
private const bool CS_INACTIVE = true;
private const bool CS_ACTIVE = false;
// SPI read/write data
private byte[] writeBuffer = new byte[1];
private byte[] readBuffer = new byte[1];
private byte[] dummy = { 0 };
// Device ID feild
public byte Manufacturer;
public byte[] Device = new byte[2];
public byte ExtendedInfoLength;
private SPI spi;
private OutputPort cs;
/// <summary>
/// Constructor for Atmel AT45DB161D data flash
/// </summary>
public AT45DB161D(SPI spiMod, OutputPort csPin, OutputPort resetPin)
{
spi = spiMod;
cs = csPin;
cs.Write(CS_INACTIVE);
// Reset AT45DB161D chip
resetPin.Write(false);
Thread.Sleep(10);
resetPin.Write(true);
}
public byte ReadStatusRegister()
{
cs.Write(CS_ACTIVE);
//Thread.Sleep(1);
// Send status read command
SPIWriteByte(STATUS_REGISTER_READ);
byte status = SPIReadByte();
cs.Write(CS_INACTIVE);
return status;
}
public void ReadManufacturerAndDeviceID()
{
cs.Write(CS_ACTIVE);
//Thread.Sleep(1);
// Send status read command
SPIWriteByte(READ_MANUFACTURER_AND_DEVICE_ID);
// Read Manufacturer ID (1FH, 31)
Manufacturer = SPIReadByte();
// Read Device ID (Part 1) (26H, 38)
Device[0] = SPIReadByte();
// Read Device ID (Part 2) (00H)
Device[1] = SPIReadByte();
// Read Extended Device Information String Length (00H)
ExtendedInfoLength = SPIReadByte();
cs.Write(CS_INACTIVE);
}
private void SPIWriteByte(byte B)
{
writeBuffer[0] = b;
spi.Write(writeBuffer);
}
private byte SPIReadByte()
{
spi.WriteRead(dummy, readBuffer);
return readBuffer[0];
}
}
}
