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DMA Timers (DTIM0–DTIM3)
30-5
Freescale Semiconductor
30.2.2
DMA Timer Extended Mode Registers (DTXMR
n
)
The DTXMR
n
registers program DMA request and increment modes for the timers.
30.2.3
DMA Timer Event Registers (DTER
n
)
DTER
n
, shown in
, reports capture or reference events by setting DTER
n
[CAP] or
DTER
n
[REF]. This reporting happens regardless of the corresponding DMA request or interrupt enable
values, DTXMR
n
[DMAEN] and DTMR
n
[ORRI,CE].
Writing a 1 to DTER
n
[REF] or DTER
n
[CAP] clears it (writing a 0 does not affect bit value); both bits can
be cleared at the same time. If configured to generate an interrupt request, clear REF and CAP early in the
interrupt service routine so the timer module can negate the interrupt request signal to the interrupt
controller. If configured to generate a DMA request, processing of the DMA data transfer automatically
clears the REF and CAP flags via the internal DMA ACK signal.
Address: 0xFC07_0002 (DTXMR0)
0xFC07_4002 (DTXMR1)
0xFC07_8002 (DTXMR2)
0xFC07_C002 (DTXMR3)
Access: User read/write
7
6
5
4
3
2
1
0
R
DMAEN
HALTED
0
0
0
0
0
MODE16
W
Reset:
0
0
0
0
0
0
0
0
Figure 30-3. DTXMR
n
Registers
Table 30-3. DTXMR
n
Field Descriptions
Field
Description
7
DMAEN
DMA request. Enables DMA request output on counter reference match or capture edge event.
0 DMA request disabled
1 DMA request enabled
6
HALTED
Controls the counter when the core is halted. This allows debug mode to be entered without timer interrupts affecting
the debug flow.
0 Timer function is not affected by core halt.
1 Timer stops counting while the core is halted.
Note:
This bit is only applicable in reference compare mode, see
Section 30.3.3, “Reference Compare.”
5–1
Reserved, must be cleared.
0
MODE16
Selects the increment mode for the timer. Setting MODE16 is intended to exercise the upper bits of the 32-bit timer
in diagnostic software without requiring the timer to count through its entire dynamic range. When set, the counter’s
upper 16 bits mirror its lower 16 bits. All 32 bits of the counter remain compared to the reference value.
0 Increment timer by 1
1 Increment timer by 65,537
Summary of Contents for MCF54455
Page 33: ...xxviii Freescale Semiconductor ...
Page 67: ...Freescale Semiconductor 1 ...
Page 125: ...Freescale Semiconductor 1 ...
Page 145: ...Enhanced Multiply Accumulate Unit EMAC 5 21 Freescale Semiconductor ...
Page 173: ...Cache 6 28 Freescale Semiconductor ...
Page 179: ...Static RAM SRAM 7 6 Freescale Semiconductor ...
Page 207: ...Power Management 9 16 Freescale Semiconductor ...
Page 323: ...Reset Controller Module 13 8 Freescale Semiconductor ...
Page 389: ...Pin Multiplexing and Control 16 44 Freescale Semiconductor ...
Page 575: ...PCI Bus Controller 22 58 Freescale Semiconductor ...
Page 600: ...Advanced Technology Attachment ATA Freescale Semiconductor 23 25 ...
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