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SPIFlash_LowPowerLab
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Removed 256 restriction from writeBytes() 

Original version was constrained by Flash 256 byte page limits.  This
change allows up to 64K writes and also deals with blocks that cross
pages (even if 2 bytes starting at address = 0xyyFF.
This commit is contained in:
TomWS1 2015-02-06 09:58:42 -05:00
parent 8d8a00c87c
commit 4616a7670c
1 changed files with 24 additions and 11 deletions
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35
SPIFlash.cpp
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@ -6,6 +6,8 @@
* Minimal modifications should allow chips that have different page size but modifications
* DEPENDS ON: Arduino SPI library
*
* Updated Jan. 5, 2015, TomWS1, modified writeBytes to allow blocks > 256 bytes and handle page misalignment.
*
* This file is free software; you can redistribute it and/or modify
* it under the terms of either the GNU General Public License version 2
* or the GNU Lesser General Public License version 2.1, both as
@ -185,20 +187,31 @@ void SPIFlash::writeByte(long addr, uint8_t byt) {
unselect();
}
/// write 1-256 bytes to flash memory
/// write multiple bytes to flash memory (up to 64K)
/// WARNING: you can only write to previously erased memory locations (see datasheet)
/// use the block erase commands to first clear memory (write 0xFFs)
/// WARNING: if you write beyond a page boundary (or more than 256bytes),
/// the bytes will wrap around and start overwriting at the beginning of that same page
/// see datasheet for more details
/// This version handles both page alignment and data blocks larger than 256 bytes.
///
void SPIFlash::writeBytes(long addr, const void* buf, uint16_t len) {
command(SPIFLASH_BYTEPAGEPROGRAM, true); // Byte/Page Program
SPI.transfer(addr >> 16);
SPI.transfer(addr >> 8);
SPI.transfer(addr);
for (uint16_t i = 0; i < len; i++)
SPI.transfer(((byte*) buf)[i]);
unselect();
int n;
int maxBytes = 256-(addr%256); // force the first set of bytes to stay within the first page
while (len>0)
{
n = (len<=maxBytes) ? len : maxBytes;
command(SPIFLASH_BYTEPAGEPROGRAM, true); // Byte/Page Program
SPI.transfer(addr >> 16);
SPI.transfer(addr >> 8);
SPI.transfer(addr);
for (uint16_t i = 0; i < n; i++)
SPI.transfer(((byte*) buf)[i]);
unselect();
addr+=n; // adjust the addresses and remaining bytes by what we've just transferred.
buf +=n;
len -= n;
maxBytes = 256; // now we can do up to 256 bytes per loop
}
}
/// erase entire flash memory array