Z86L81 Datasheet, PDF (52/88 Pages) Maxim Integrated Products – 28-Pin Low-Voltage Infrared Microcontrollers

Z86L81/86/98
28-Pin Low-Voltage Infrared Microcontrollers
46
This T16 mode is generally used to measure mark time, defined as the length of
time between carrier signal bursts (marks).
If D6 of CTR2 Is 1
T16 ignores the subsequent edges in the input signal and continues counting
down. A timeout of T8 causes T16 to capture its current value and generate an
interrupt if enabled (CTR2, D2). In this case, T16 does not reload and continues
counting. If the D6 bit of CTR2 is toggled (by writing a 0 then a 1 to it), T16 cap-
tures and reloads on the next edge (rising, falling, or both depending on CTR1,
D5; D4), thereby continuing to ignore subsequent edges.
This T16 mode is generally used to measure mark time, defined as the length of
time between carrier signal bursts (marks).
If T16 reach 0, T16 continues counting from FFFFh. Meanwhile, a status bit (CTR2
D5) is set, and an interrupt timeout can be generated if enabled (CTR2 D1).
Ping-Pong Mode
This operation mode is only valid in Transmit Mode. T8 and T16 must be pro-
grammed in Single-Pass Mode (CTR0, D6, CTR2, D6) and Ping-Pong Mode must
be programmed in CTR1, D3; D2. The user can begin the operation by enabling
either T8 or T16 (CTR0, D7 or CTR2, D7). For example, if T8 is enabled, T8_OUT
is set to this initial value (CTR1, D1). According to T8_OUT's level, TC8H or TC8L
is loaded into T8. After the terminal count is reached, T8 is disabled and T16 is
enabled. T16_OUT switches to its initial value (CTR1, D0), data from TC16H and
TC16L is loaded, and T16 starts to count. After T16 reaches the terminal count, it
stops, T8 is enabled again, and the whole cycle repeats. Interrupts can be allowed
when T8 or T16 reaches terminal control (CTR0, D1; CTR2, D1). To stop the Ping-
Pong operation, write 00 to bits D3 and D2 of CTR1. See Figure 24.
Note: Enabling Ping-Pong operation while the counter/timers are
running might cause intermittent counter/timer function. Disable
the counter/timers and then reset the status flags before
instituting this operation.
19-4615; Rev 0; 4/09