need help checkin on waveform...

i using infrared encoder for infrared transmition.but suspect the code is faulthy.below is the waveform get from pin TXIR from MCP2120.TX is the data from microchip in data rate 9600.n TXIR is the encoded data with hardware data rate selection 9600.

i also attached a enlarged waveform to know the pulsewidth of TXIR.waveform shown 1.8us.wat i calculate supposed is 19.5us.is it consider wrong?

more info...

i attached my schematic diagram in case anybody know whether there is wrong with my circuit connection