CY8C28xxx PSoC Programmable System-on-Chip TRM, Document No. 001-52594 Rev. *G
83
Internal Main Oscillator (IMO)
on the order of 50 ms. After lock is achieved, it is recom-
mended that this bit be forced high to decrease the jitter on
the output. If longer lock time is tolerable, the PLLGAIN bit
can be held high all the time.
Bit 4: SLP_EXTEND.
This bit allows for extended sleep
intervals, up to 16s.
Bit 3: WDR32_SE.
If an external 32 kHz crystal is used,
this bit allows a choice between the ECO or the ILO as the
source of the watchdog timer and sleep timer
Bit 2: EXTCLKEN.
When the EXTCLKEN bit is set, the
external clock becomes the source for the internal clock
tree, SYSCLK, which drives most PSoC device clocking
functions. All external and internal signals, including the
32-kHz clock, whether derived from the Internal Low Speed
Oscillator (ILO) or the crystal oscillator, are synchronized to
this clock source. If an external clock is enabled, PLL mode
should be off. The external clock input is located on port
P1[4]. When using this input, the pin drive mode should be
set to High-Z (not High-Z analog).
Bit 1: RSVD.
Reserved bit - This bit should always be 0.
Bit 0: SYSCLKX2DIS.
When SYSCLKX2DIS is set, the
IMO’s doubler is disabled. This will result in a reduction of
overall device power, on the order of 1 mA. It is advised that
any application that does not require this doubled clock
should have it turned off.
For additional information, refer to the
8.3.3
IMO_TR Register
The Internal Main Oscillator Trim Register (IMO_TR) is used
to manually center the oscillator’s output to a target fre-
quency.
The PSoC device specific value for 5-V operation is loaded
into the Internal Main Oscillator Trim register (IMO_TR) at
boot time. The Internal Main Oscillator will operate within
specified tolerance over a voltage range of 4.75 V to 5.25 V,
with no modification of this register. If the PSoC device is
operated at a lower voltage, user code must modify the con-
tents of this register. For operation in the voltage range of
3.3 V ± 0.3 V, this is accomplished with a Table Read com-
mand to the Supervisory ROM, which will supply a trim
value for operation in this range. For operation between
these voltage ranges, user code can interpolate the best
value using both available factory trim values.
It is strongly recommended that the user not alter the
register value, unless Slow IMO mode is used.
Bits 7 to 0: Trim[7:0].
These bits are used to trim the Inter-
nal Main Oscillator. A larger value in this register will
increase the speed of the oscillator.
For additional information, refer to the
8.3.4
IMO_TR1 Register
The Internal Main Oscillator Trim 1 Register (IMO_TR1) is
used to tune CATA current.
Bits 1 to 0: CATA_Trim[1:0].
These bits are used to tune
CATA current.
‘00’ is for largest CATA current (default value).
...
‘11’ is for smallest CATA current.
For additional information, refer to the
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Access
1,E8h
Trim[7:0]
RW : 00
Address
Name
Bit 7
Bit 6
Bit 5
Bit 4
Bit 3
Bit 2
Bit 1
Bit 0
Access
1,EFh
CATA_Trim[1:0]
RW : 0
Содержание CY8C28 series
Страница 65: ...64 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G RAM Paging ...
Страница 85: ...84 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Internal Main Oscillator IMO ...
Страница 93: ...92 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G External Crystal Oscillator ECO ...
Страница 97: ...96 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Phase Locked Loop PLL ...
Страница 125: ...124 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G ...
Страница 311: ...310 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G IDAC_CR0 1 FDh ...
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Страница 425: ...424 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Analog Reference ...
Страница 461: ...460 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Two Column Limited Analog System ...
Страница 477: ...476 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Digital Clocks ...
Страница 483: ...482 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Multiply Accumulate MAC ...
Страница 513: ...512 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Internal Voltage Reference ...
Страница 523: ...522 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Switch Mode Pump SMP ...
Страница 533: ...532 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G I O Analog Multiplexer ...
Страница 537: ...536 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G Real Time Clock RTC ...
Страница 561: ...560 CY8C28xxx PSoC Programmable System on Chip TRM Document No 001 52594 Rev G ...