Datasheet

TIR1000, TIR1000I
STANDALONE IrDA ENCODER AND DECODER
SLLS228F – DECEMBER 1995 – REVISED JULY 1999
6
POST OFFICE BOX 655303 • DALLAS, TEXAS 75265
PRINCIPLES OF OPERATION
IrDA encoder function (continued)
The TIR1000 and TIR1000I can decode positive pulses on IR_RXD. The timing is different, but the variation
is invisible to the UART. The decoder, which works from the falling edge, now recognizes a zero on the trailing
edge of the pulse rather than on the leading edge. As long as the pulse width is fairly constant, as defined by
the specification, the trailing edges should also be 16 clock cycles apart and data can readily be decoded. The
zero appears on U_RXD after the pulse rather than at the start of it.
12345678 10 12 14 16
IR_RXD
16XCLK
U_RXD
Figure 8. Positive IR_RXD Pulse Decode – Detailed View
16
Cycles
16
Cycles
16
Cycles
16
Cycles
16XCLK
IR_RXD
U_RXD
Figure 9. Positive IR_RXD Pulse Decode – Macro View