Transfer Counter Is Zero Interrupt

The Transfer Counter Is Zero Interrupt Flag and Transfer Counter Is Zero Interrupt Enable are the TCZIF and TCZIE bits, respectively. This interrupt will trigger when the transfer counter (defined by BMODE, SPIxTCNT and SPIxTWIDTH) decrements from one to zero. See Figure 1 for more details on the timing of this interrupt as well as other interrupts. This bit must be cleared in software.

The TCZIF flag only indicates that the transfer counter has decremented from one to zero, and may not indicate that the entire data transfer process is complete. Either poll the BUSY bit and wait for it to be cleared or use the Shift Register Empty Interrupt (SRMTIF) to determine when a data transfer is fully complete.