Z86L79 Datasheet, PDF (35/58 Pages) Zilog, Inc. – Low-Voltage Microcontroller

Zilog
TC16H*256+TC16L Counts
Z86L79/80
Low-Voltage Microcontroller
1
T16_OUT
“Counter Enable” Command,
T16_OUT Switches To Its
Initial Value (CTR1 D0)
T16_OUT Toggles,
Time-Out Interrupt
Figure 26. T16_OUT in Single-Pass Mode
TC16H*256+TC16L
TC16H*256+TC16L
TC16H*256+TC16L
“Counter Enable” Command,
T16_OUT Switches To Its
Initial Value (CTR1 D0)
T16_OUT Toggles,
Time-Out Interrupt
Figure 27. T16_OUT in Modulo-N Mode
T16_OUT Toggles,
Time-Out Interrupt
T16 Demodulation Mode
The user should program TC16L and TC16H to %FF. After
T16 is enabled, when the first edge (rising, falling, or both
depending on CTR1 D5, D4) is detected, begins to count
down.
If D6 of CTR2 is 0: When a subsequent edge (rising, fall-
ing, or both depending on CTR1 D5, D4) is detected during
counting, the current count in T16 is one's complemented
and put into HI16 and LO16. When data is captured, one
of the edge detect status bits (CTR1 D1, D0) is set and an
interrupt is generated if enabled (CTR2 D2). T16 is loaded
with %FFFF and starts again.
If D6 of CTR2 is 1: T16 ignores the subsequent edges in
the input signal and continues counting down. A time out
of T8 will cause T16 to capture its current value and gen-
erate an interrupt if enabled (CTR2, D2). In this case, T16
does not reload and continues counting. If D6 bit of CTR2
is toggled (by writing a 0 then a 1 to it), T16 will capture and
reload on the next edge (rising, falling, or both depending
on CTR1 D5, D4) but continue to ignore subsequent edg-
es.
Should T16 reach 0, it continues counting from %FFFF;
meanwhile, a status bit (CTR2 D5) is set and an interrupt
time-out can be generated if enabled (CTR2 D1).
PRELIMINARY
3-35