XC164-16 Datasheet, PDF (49/417 Pages) Infineon Technologies AG – 16-Bit Single-Chip Microcontroller with C166SV2 Core Volume 2 (of 2): Peripheral Units

XC164-16 Derivatives
Peripheral Units (Vol. 2 of 2)
The General Purpose Timer Units
Timer 6 Output Toggle Latch
The overflow/underflow signal of timer T6 is connected to a block named ‘Toggle Latch’,
shown in the timer mode diagrams. Figure 14-21 illustrates the details of this block. An
overflow or underflow of T6 will clock two latches: The first latch represents bit T6OTL in
control register T6CON. The second latch is an internal latch toggled by T6OTL’s output.
Both latch outputs are connected to the input control block of the auxiliary timer T5. The
output level of the shadow latch will match the output level of T6OTL, but is delayed by
one clock cycle. When the T6OTL value changes, this will result in a temporarily different
output level from T6OTL and the shadow latch, which can trigger the selected count
event in T5.
When software writes to T6OTL, both latches are set or cleared simultaneously. In this
case, both signals to the auxiliary timers carry the same level and no edge will be
detected. Bit T6OE (overflow/underflow output enable) in register T6CON enables the
state of T6OTL to be monitored via an external pin T6OUT. When T6OTL is linked to an
external port pin (must be configured as output), T6OUT can be used to control external
HW. If T6OE = 1, pin T6OUT outputs the state of T6OTL. If T6OE = 0, pin T6OUT
outputs a high level (while it selects the timer output signal).
As can be seen from Figure 14-21, when latch T6OTL is modified by software to
determine the state of the output line, also the internal shadow latch is set or cleared
accordingly. Therefore, no trigger condition is detected by T5 in this case.
Set/Clear (SW )
TxOE
O verflow/
Core Tim er ^Underflow
TxOTL
Shadow
Latch
1
10
TxOUT
To Port Logic
Toggle Latch Logic
To Aux. Timer
Input Logic
m c_gpt0106_otl.vsd
Figure 14-21 Block Diagram of the Toggle Latch Logic of Core Timer T6
Note: T6 is also used to clock the timers in the CAPCOM units. For this purpose, there
is a direct internal connection between the T6 overflow/underflow line and the
CAPCOM timers (signal T6OUF).
User’s Manual
GPT_X41, V2.0
14-36
V2.1, 2004-03