User manual

Timers
MPC8260 PowerQUICC II Family Reference Manual, Rev. 2
Freescale Semiconductor 18-5
Table 18-2 describes TGCR2 fields.
18.2.3 Timer Mode Registers (TMR1–TMR4)
The four timer mode registers (TMR1–TMR4) are shown in Figure 18-5.
Erratic behavior may occur if TGCR1 and TGCR2 are not initialized before the TMRs. Only TGCR[RST]
can be modified at any time.
01234567
Field CAS4 — STP4 RST4 GM2 — STP3 RST3
Reset 0000_0000
R/W R/W
Addr 0x0x10D84
Figure 18-4. Timer Global Configuration Register 2 (TGCR2)
Table 18-2. TGCR2 Field Descriptions
Bit Name Description
0 CAS4 Cascade timers.
0 Normal operation.
1 Timers 3 and 4 cascades to form a 32-bit timer.
1 — Reserved, should be cleared.
2 STP 4 Stop timer.
0 Normal operation.
1 Reduce power consumption of the timer. This bit stops all clocks to the timer, except the clock
from the internal bus interface, which allows the user to read and write timer registers. The clocks
to the timer remain stopped until the user clears this bit or a hardware reset occurs.
3 RST4 Reset timer.
0 Reset the corresponding timer (a software reset is identical to an external reset).
1 Enable the corresponding timer if the STP bit is cleared.
4 GM2 Gate mode for TGATE2
. This bit is valid only if the gate function is enabled in TMR3 or TMR4.
0 Restart gate mode. TGATE2
is used to enable/disable the count. The falling edge of TGATE2
enables and restarts the count and the rising edge of TGATE2
disables the count.
1 Normal gate mode. This mode is the same as 0, except the falling edge of TGATE2
does not
restart the count value in TCN.
5 — Reserved, should be cleared.
6 STP3 Stop timer.
0 Normal operation.
1 Reduce power consumption of the timer. This bit stops all clocks to the timer, however it is
possible to read the values while the clock is stopped. The clocks to the timer remain stopped
until the user clears this bit or a hardware reset occurs.
7 RST3 Reset timer.
0 Reset the corresponding timer (a software reset is identical to an external reset).
1 Enable the corresponding timer if STP = 0.