Add API to enable NVM writes.

When using single-writes (writeWord()) only write if the destination has changed.

2 files changed, 25 insertions, 9 deletions

diff --git a/libs/NVRam/include/NVRam.h b/libs/NVRam/include/NVRam.h
index 3d995ff..a3d5378 100644
--- a/libs/NVRam/include/NVRam.h
+++ b/libs/NVRam/include/NVRam.h
@@ -58,7 +58,9 @@ void NVRam_writeWord(uint32_t address, uint32_t data);
 void NVRam_write(uint32_t address, uint32_t *buffer, size_t words);
 
 void NVRam_enable(void);
+void NVRam_enableWrites(void);
 void NVRam_disable(void);
+void NVRam_disableWrites(void);
 
 uint32_t NVRam_crc(uint8_t *pcDatabuf, // Pointer to data buffer
                    uint32_t ulDatalen, // Length of data buffer in bytes
diff --git a/libs/NVRam/nvm.c b/libs/NVRam/nvm.c
index a2d68b6..9e69ecc 100644
--- a/libs/NVRam/nvm.c
+++ b/libs/NVRam/nvm.c
@@ -90,16 +90,25 @@ static inline uint32_t NVRam_translate(uint32_t address)
 
 void NVRam_enable(void)
 {
-    // TODO: enable both bits on read.
     NVM.Access.bits.Enable = 1;
 }
 
+void NVRam_enableWrites(void)
+{
+    NVM.Access.bits.WriteEnable = 1;
+}
+
 void NVRam_disable(void)
 {
-    // TODO: enable both bits on read.
     NVM.Access.bits.Enable = 0;
 }
 
+void NVRam_disableWrites(void)
+{
+    NVM.Access.bits.WriteEnable = 0;
+}
+
+
 static inline void NVRam_waitDone(void)
 {
     while (!NVM.Command.bits.Done)
@@ -214,14 +223,19 @@ void NVRam_read(uint32_t address, uint32_t *buffer, size_t words)
 
 void NVRam_writeWord(uint32_t address, uint32_t data)
 {
-    RegNVMCommand_t cmd;
-    cmd.r32 = 0;
-    cmd.bits.First = 1;
-    cmd.bits.Last = 1;
-    cmd.bits.Doit = 1;
-    cmd.bits.Wr = 1;
+    if(data !=  NVRam_readWord(address))
+    {
+        // Only write if different.
 
-    NVRam_writeWordInternal(address, data, cmd);
+        RegNVMCommand_t cmd;
+        cmd.r32 = 0;
+        cmd.bits.First = 1;
+        cmd.bits.Last = 1;
+        cmd.bits.Doit = 1;
+        cmd.bits.Wr = 1;
+
+        NVRam_writeWordInternal(address, data, cmd);
+    }
 }
 
 void NVRam_write(uint32_t address, uint32_t *buffer, size_t words)