MC9S12XD256MAL Datasheet, PDF (548/1348 Pages) Freescale Semiconductor, Inc – Freescale’s Scalable Controller Area Network

Chapter 13 Periodic Interrupt Timer (S12PIT24B4CV1)
13.3.0.6 PIT Time-Out Flag Register (PITTF)
7
6
5
4
R
0
0
0
0
W
Reset
0
0
0
0
= Unimplemented or Reserved
3
PTF3
0
2
PTF2
0
Figure 13-8. PIT Time-Out Flag Register (PITTF)
Read: Anytime
Write: Anytime (write to clear); writes to the reserved bits have no effect
Table 13-6. PITTF Field Descriptions
1
PTF1
0
0
PTF0
0
Field
3:0
PTF[3:0]
Description
PIT Time-out Flag Bits for Timer Channel 3:0 — PTF is set when the corresponding 16-bit timer modulus
down-counter and the selected 8-bit micro timer modulus down-counter have counted to zero. The flag can be
cleared by writing a one to the flag bit. Writing a zero has no effect. If flag clearing by writing a one and flag setting
happen in the same bus clock cycle, the flag remains set. The flag bits are cleared if the PIT module is disabled
or if the corresponding timer channel is disabled.
0 Time-out of the corresponding PIT channel has not yet occurred.
1 Time-out of the corresponding PIT channel has occurred.
13.3.0.7 PIT Micro Timer Load Register 0 to 1 (PITMTLD0–1)
R
W
Reset
7
PMTLD7
0
6
PMTLD6
5
PMTLD5
4
PMTLD4
3
PMTLD3
2
PMTLD2
1
PMTLD1
0
0
0
0
0
0
Figure 13-9. PIT Micro Timer Load Register 0 (PITMTLD0)
0
PMTLD0
0
R
W
Reset
7
PMTLD7
0
6
PMTLD6
5
PMTLD5
4
PMTLD4
3
PMTLD3
2
PMTLD2
1
PMTLD1
0
0
0
0
0
0
Figure 13-10. PIT Micro Timer Load Register 1 (PITMTLD1)
0
PMTLD0
0
Read: Anytime
Write: Anytime
Table 13-7. PITMTLD0–1 Field Descriptions
Field
Description
7:0
PMTLD[7:0]
PIT Micro Timer Load Bits 7:0 — These bits set the 8-bit modulus down-counter load value of the micro timers.
Writing a new value into the PITMTLD register will not restart the timer. When the micro timer has counted down
to zero, the PMTLD register value will be loaded. The PFLMT bits in the PITCFLMT register can be used to
immediately update the count register with the new value if an immediate load is desired.
MC9S12XDP512 Data Sheet, Rev. 2.21
548
Freescale Semiconductor