Slow AVRISP-MKII clone PDI/TPI programming speed back to 250KHz due to issues with the XPLAINBridge when PDI programming at faster rates.

Speed up XMEGANVM_WaitWhileNVMControllerBusy() by preloading the status register address into the pointer register of the target's NVM controller and then reading via a faster indirect load command.
This commit is contained in:
Dean Camera 2010-11-16 12:30:00 +00:00
parent 002cd6df49
commit a9f313afa9
4 changed files with 10 additions and 9 deletions

View file

@ -96,13 +96,15 @@ bool XMEGANVM_WaitWhileNVMBusBusy(void)
*/
bool XMEGANVM_WaitWhileNVMControllerBusy(void)
{
/* Preload the pointer register with the NVM STATUS register address to check the BUSY flag */
XPROGTarget_SendByte(PDI_CMD_ST | (PDI_POINTER_DIRECT << 2) | PDI_DATSIZE_4BYTES);
XMEGANVM_SendNVMRegAddress(XMEGA_NVM_REG_STATUS);
/* Poll the NVM STATUS register while the NVM controller is busy */
for (;;)
{
/* Send a LDS command to read the NVM STATUS register to check the BUSY flag */
XPROGTarget_SendByte(PDI_CMD_LDS | (PDI_DATSIZE_4BYTES << 2));
XMEGANVM_SendNVMRegAddress(XMEGA_NVM_REG_STATUS);
/* Fetch the current status value via the pointer register (without auto-increment afterwards) */
XPROGTarget_SendByte(PDI_CMD_LD | (PDI_POINTER_INDIRECT << 2) | PDI_DATSIZE_1BYTE);
uint8_t StatusRegister = XPROGTarget_ReceiveByte();
/* We might have timed out waiting for the status register read response, check here */