CYRF69103_13 Datasheet, PDF (25/72 Pages) Cypress Semiconductor – Programmable Radio on Chip Low Power

CYRF69103
Clocking
The CYRF69103 internal oscillator outputs two frequencies, the
Internal 24 MHz Oscillator and the 32 kHz Low power Oscillator.
The Internal 24 MHz Oscillator is designed such that it may be
trimmed to an output frequency of 24 MHz over temperature and
voltage variation. The Internal 24 MHz Oscillator accuracy is 24
MHz –22% to +10% (between 0 °C–70 °C). No external compo-
nents are required to achieve this level of accuracy.
Firmware is responsible for selecting the correct trim values from
the User row to match the power supply voltage in the end appli-
cation and writing the values to the trim registers IOSCTR and
LPOSCTR.
The internal low speed oscillator of nominally 32 kHz provides a
slow clock source for the CYRF69103 in suspend mode. This is
used to generate a periodic wakeup interrupt and provide a clock
to sequential logic during power up and power down events
when the main clock is stopped. In addition, this oscillator can
also be used as a clocking source for the Interval Timer clock
(ITMRCLK) and Capture Timer clock (TCAPCLK). The 32 kHz
Low power Oscillator can operate in low power mode or can
provide a more accurate clock in normal mode. The Internal 32
kHz Low power Oscillator accuracy ranges from –53.12% to
+56.25%. The 32 kHz low power oscillator can be calibrated
against the internal 24 MHz oscillator or another timing source if
desired.
CYRF69103 provides the ability to load new trim values for the
24 MHz oscillator based on voltage. This allows Vdd to be
monitored and have firmware trim the oscillator based on voltage
present. The IOSCTR register is used to set trim values for the
24 MHz oscillator. CYRF69103 is initialized with 3.30V trim
values at power on, then firmware is responsible for transferring
the correct set of trim values to the trim registers to match the
application’s actual Vdd. The 32 kHz oscillator generally does
not require trim adjustments versus voltage but trim values for
the 32 kHz are also stored in Supervisory ROM.
Figure 10. SROM Table
F8h
F9h
FAh
FBh
FCh
FDh
FEh
FFh
Table 0
Silicon ID
[15-8]
Silicon ID
[7-0]
Table 1
Table 2
ROegpieornaVtainligd
24 MHz
IOSCTR
at 3.30V
24 MHz
IOSCTR
at 3.00V
24 MHz
IOSCTR
at 2.85V
24 MHz
IOSCTR
at 2.70V
32 kHz 32 kHz 32 kHz 32 kHz
Table 3 LPOSCTR LPOSCTR LPOSCTR LPOSCTR
at 3.30V at 3.00V at 2.85V at 2.70V
Table 4
Table 5
Table 6
Table 7
To improve the accuracy of the IMO, new trim values are loaded based on supply voltage to the part. For this, firmware needs to make
modifications to two registers:
1. The internal oscillator trim register at location 0x34.
2. The gain register at location 0x38.
Document Number: 001-07611 Rev *I
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