Architecture
MSC8113 Reference Manual, Rev. 0
Freescale Semiconductor
4-5
4.1.4 Periodic Interrupt Timer (PIT)
The periodic interrupt timer consists of a 16-bit counter clocked by
TIMERSCLK
. The 16-bit
counter decrements to zero when loaded with a value from the Periodic Interrupt Timer Count
Register (PITC). After the timer reaches zero, PISCR[PS] is set and an interrupt is generated if
PISCR[PIE] = 1. At the next input clock edge, the value in the PITC is loaded into the counter
and the process repeats. When a new value is loaded into the PITC, the PIT is updated, the
divider is reset, and the counter begins counting. Setting PISCR[PS] creates a pending interrupt
that remains pending until PS is cleared. If PS is set again before being cleared, the interrupt
remains pending until PS is cleared. Any write to the PITC stops the current countdown, and the
count resumes with the new value in PITC. If PISCR[PTE] = 0, the PIT cannot count and retains
the old count value. The PIT is unaffected by reads. Figure 4-5 shows a block diagram of the
PIT.
Figure 4-4. TMCNT Block Diagram
Figure 4-5. PIT Block Diagram
Divide
(32-Bit Counter)
(32-Bit Register)
SEC
Alarm
=
Interrupt
Interrupt
by 8192
TIMERSCLK for TMCNT (8,192 Hz)
Time Counter (TMCNT)
Time Counter Alarm Register (TMCNTAL)
Alarm
Interrupt
Logic
Clock
PITC
TIMERSCLK
PISCR[PS]
PISCR[PIE]
PIT
PISCR[PTE]
Disable
for PIT
16-Bit Modulus
Interrupt
Counter
Summary of Contents for MSC8113
Page 1: ...MSC8113 Reference Manual Tri Core 16 Bit Digital Signal Processor MSC8113RM Rev 0 May 2008 ...
Page 20: ...MSC8113 Reference Manual Rev 0 xx Freescale Semiconductor Contents ...
Page 28: ...MSC8113 Reference Manual Rev 0 xxviii Freescale Semiconductor ...
Page 56: ...MSC8113 Reference Manual Rev 0 1 28 Freescale Semiconductor MSC8113 Overview ...
Page 76: ...MSC8113 Reference Manual Rev 0 2 20 Freescale Semiconductor SC140 Core Overview ...
Page 134: ...MSC8113 Reference Manual Rev 0 4 30 Freescale Semiconductor System Interface Unit SIU ...
Page 168: ...MSC8113 Reference Manual Rev 0 6 18 Freescale Semiconductor Boot Program ...
Page 180: ...MSC8113 Reference Manual Rev 0 7 12 Freescale Semiconductor Clocks ...
Page 260: ...MSC8113 Reference Manual Rev 0 8 80 Freescale Semiconductor Memory Map ...
Page 300: ...MSC8113 Reference Manual Rev 0 9 40 Freescale Semiconductor Extended Core ...
Page 304: ...MSC8113 Reference Manual Rev 0 10 4 Freescale Semiconductor MQBus and M2 Memory ...
Page 308: ...MSC8113 Reference Manual Rev 0 11 4 Freescale Semiconductor SQBus ...
Page 590: ...MSC8113 Reference Manual Rev 0 17 46 Freescale Semiconductor Interrupt Processing ...
Page 614: ...MSC8113 Reference Manual Rev 0 18 24 Freescale Semiconductor Debugging ...
Page 622: ...MSC8113 Reference Manual Rev 0 19 8 Freescale Semiconductor Internal Peripheral Bus IPBus ...
Page 724: ...MSC8113 Reference Manual Rev 0 21 32 Freescale Semiconductor UART ...
Page 920: ...MSC8113 Reference Manual Rev 0 25 150 Freescale Semiconductor Ethernet Controller ...
Page 1171: ...MSC8113 Reference Manual Rev 0 Freescale Semiconductor C 61 EF wait_rts P 01077FFC 9F rts 71 ...
Page 1172: ...MSC8113 Reference Manual Rev 0 C 62 Freescale Semiconductor MSC8113 Boot Code ...
Page 1202: ...MSC8113 Reference Manual Rev 0 Index 30 Freescale Semiconductor Index ...