if (downlink_mode == T55xx_DLMode_LLR)
T55xxWriteBit (T55xx_LongLeadingReference,Timing); // Send Long Leading Start Reference
- if (downlink_mode == T55xx_DLMode_1of4) { // 1 of 4 need to send 2 bits at a time
+ if ((downlink_mode == T55xx_DLMode_1of4) && (BitStreamLen > 0)) { // 1 of 4 need to send 2 bits at a time
for ( i = 0; i < BitStreamLen-1; i+=2 ) {
SendBits = (BitStream[BitStream_Byte(i )] >> (BitStream_Bit(i )) & 1) << 1; // Bit i
SendBits += (BitStream[BitStream_Byte(i+1)] >> (BitStream_Bit(i+1)) & 1); // Bit i+1;