Diff: fram/fram.c

Revision:

106:41ed3ea0bbba

Parent:

105:1899f7ed17ec

diff -r 1899f7ed17ec -r 41ed3ea0bbba fram/fram.c
--- a/fram/fram.c	Tue Feb 23 20:35:07 2021 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,143 +0,0 @@
-#include <string.h>
-#include <stdbool.h>
-
-#include "spi.h"
-#include "log.h"
-#include "fram.h"
-
-#define WREN  0x06 // Set Write Enable Latch   0000 0110B
-#define WRDI  0x04 // Reset Write Enable Latch 0000 0100B
-#define RDSR  0x05 // Read Status Register     0000 0101B
-#define WRSR  0x01 // Write Status Register    0000 0001B
-#define READ  0x03 // Read Memory Code         0000 0011B
-#define WRITE 0x02 // Write Memory Code        0000 0010B
-#define RDID  0x9F // Read Device ID           1001 1111B
-
-#define FRAM_ID     0x047f0302
-#define FRAM_MAGIC  42          //Magic number to show that the FRAM has been intialised
-
-bool FramEmpty; //Set in FramInit
-int  FramUsed;  //Initialised in FramInit and used by FramAllocate to remember the next available location
-
-int FramAllocate(int size) //Allocates a number of bytes in FRAM 
-{
-    int start = FramUsed;
-    int used = FramUsed + size;
-    if (used > FRAM_SIZE - 1)
-    {
-        Log("FramAllocate - No more room in FRAM\r\n");
-        return -1;
-    }
-    FramUsed = used;
-    return start;
-}
-int FramInit()
-{
-    //Configure SPI
-    SpiInit();
-    
-    //Check if the FRAM is connected and working properly
-    SpiChipSelect(0);
-    SpiTransfer(RDID);
-    int id = 0;
-    id = (id << 8) + SpiTransfer(0);
-    id = (id << 8) + SpiTransfer(0);
-    id = (id << 8) + SpiTransfer(0);
-    id = (id << 8) + SpiTransfer(0);
-    SpiChipSelect(1);
-    if (id != FRAM_ID)
-    {
-        LogF("FramInit - Expected FRAM id %08x but got %08x\r\n", FRAM_ID, id);
-        return -1;
-    }
-    
-    //Check the first byte to see if the FRAM is initialised and zero if not
-    SpiChipSelect(0);
-    SpiTransfer(READ);
-    SpiTransfer(0);
-    SpiTransfer(0);
-    char magic = SpiTransfer(0);
-    SpiChipSelect(1);
-    FramEmpty = magic != FRAM_MAGIC;
-    if (FramEmpty)
-    {
-        LogF("FramInit - Byte 0 value %d is not the magic value %d so initialising FRAM to zero\r\n", magic, FRAM_MAGIC);
-        SpiChipSelect(0);
-        SpiTransfer(WREN);
-        SpiChipSelect(1); SpiChipSelect(1); SpiChipSelect(1); SpiChipSelect(1); SpiChipSelect(1); SpiChipSelect(1);
-        SpiChipSelect(0);
-        SpiTransfer(WRITE);
-        SpiTransfer(0);
-        SpiTransfer(0);
-        SpiTransfer(FRAM_MAGIC);                           //Set the magic number in byte 0
-        for(int i = 1; i < FRAM_SIZE; i++) SpiTransfer(0); //Zero all other locations
-        SpiChipSelect(1);
-    }
-    FramUsed = 1; //Set the next available location to one past the byte used for the magic number
-    return 0;
-}
-void FramWrite(int address, int len, void* pVoid)
-{
-    if (address + len > FRAM_SIZE - 1 || address < 0)
-    {
-        Log("FramWrite - Invalid FRAM address\r\n");
-        return;
-    }
-    SpiChipSelect(0);
-    SpiTransfer(WREN);
-    SpiChipSelect(1); SpiChipSelect(1); SpiChipSelect(1); SpiChipSelect(1); SpiChipSelect(1); SpiChipSelect(1); //Deselect must be at least 60ns. One operation at 96MHz is about 10ns
-    SpiChipSelect(0);
-    SpiTransfer(WRITE);
-    SpiTransfer(address >> 8);
-    SpiTransfer(address & 0xFF);
-    char* p = (char*)pVoid;
-    for (int i = 0; i < len; i++) SpiTransfer(*p++);
-    SpiChipSelect(1);
-}
-void FramRead(int address, int len, void* pVoid)
-{
-    if (address + len > FRAM_SIZE - 1 || address < 0)
-    {
-        Log("FramRead - Invalid FRAM address\r\n");
-        return;
-    }
-    SpiChipSelect(0);
-    SpiTransfer(READ);
-    SpiTransfer(address >> 8);
-    SpiTransfer(address & 0xFF);
-    char* p = (char*)pVoid;
-    for (int i = 0; i < len; i++) *p++ = SpiTransfer(0);
-    SpiChipSelect(1);
-}
-
-int FramLoad(int len, void* pValue, void* pDefault)
-{
-    int address = FramAllocate(len);
-    if (address >= 0) 
-    {
-        if (FramEmpty)
-        {
-            if (pDefault)
-            {
-                int defaultHasContent = 0;
-                char* pFrom = (char*)pDefault;
-                char* pTo   = (char*)pValue;
-                for (int i = 0; i < len; i++)
-                {
-                    if (*pFrom) defaultHasContent = 1;
-                    *pTo++ = *pFrom++;
-                }
-                if (defaultHasContent) FramWrite(address, len, pValue);
-            }
-            else //pDefault is NULL so zero the setting
-            {
-                memset(pValue, 0, len);
-            }
-        }
-        else
-        {
-            FramRead(address, len, pValue);
-        }
-    }
-    return address;
-}