Added reliability patches to the AVRISP-MKII Clone project's PDI/TPI protocols (thank...

[pub/USBasp.git] / Projects / AVRISP-MKII / Lib / XPROG / XMEGANVM.c

diff --git a/Projects/AVRISP-MKII/Lib/XPROG/XMEGANVM.c b/Projects/AVRISP-MKII/Lib/XPROG/XMEGANVM.c
index e4f1186..71fa782 100644 (file)
--- a/Projects/AVRISP-MKII/Lib/XPROG/XMEGANVM.c
+++ b/Projects/AVRISP-MKII/Lib/XPROG/XMEGANVM.c
@@ -149,13 +149,18 @@ void XMEGANVM_DisablePDI(void)
 {
        XMEGANVM_WaitWhileNVMBusBusy();
 
-       /* Clear the RESET key in the RESET PDI register to allow the XMEGA to run */
-       XPROGTarget_SendByte(PDI_CMD_STCS | PDI_RESET_REG);
-       XPROGTarget_SendByte(0x00);
-
-       /* Do it twice to make sure it takes effect (silicon bug?) */
-       XPROGTarget_SendByte(PDI_CMD_STCS | PDI_RESET_REG);
-       XPROGTarget_SendByte(0x00);
+       /* Clear the RESET key in the RESET PDI register to allow the XMEGA to run - must perform this until the 
+        * change takes effect, as in some cases it takes multiple writes (silicon bug?).
+        */
+       do
+       {
+               /* Clear reset register */
+               XPROGTarget_SendByte(PDI_CMD_STCS | PDI_RESET_REG);
+               XPROGTarget_SendByte(0x00);
+       
+               /* Read back the reset register, check to see if it took effect */
+               XPROGTarget_SendByte(PDI_CMD_LDCS | PDI_RESET_REG);
+       } while (XPROGTarget_ReceiveByte() != 0x00);
 
        XPROGTarget_DisableTargetPDI();
 }