CY4636 WirelessUSB™ LP Keyboard Mouse Reference Design Kit User Guide, Doc. # 001-70355 Rev. *A
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Code Examples
Figure 5-15. Device Configuration for LP_RDK_Mouse
5.2.2.1
Global Configuration
Following is a description of the Global Resources that are configured for the CY7C60323-PVXC
enCoRe III LV microcontroller. Care must be taken when modifying these values as they affect the
following User Modules.
Power Setting / System Clock Frequency.
The mouse is powered using the Power Management
Unit on the CYRF6936 radio chip. The default configuration of the radio PMU is used to power the
microcontroller at 2.7 volts. The microcontroller power setting is set to 2.7 V/12 MHz.
CPU Clock.
This parameter is set to SysClk/1 in order to run the CPU at 12 MHz. This operating
frequency provides for faster code execution, when events are detected, so the microcontroller can
be put back into sleep mode for improved power savings. Slower clock frequencies increase power
consumption of the microcontroller in the mouse design.
Sleep Timer.
The sleep timer is set to 1 Hz in order to reduce the microcontroller load. The sleep
timer is used to maintain a very coarse sense of time when the PWM User Module is turned off.
Changing this value affects timing operation of the timer code module.
VC1 - VC3.
The other clock sources are set to provide optimal performance for the SPI User Mod-
ule and the ADC. Since there is a dependency of VC3 on VC2, VC2 on VC1 and VC1 on System
Clock, changing of these parameters have a cascading affect. VC1 is configured for SysClk / 2. VC2
is configured for VC1/3 and is used to clock the SPI User Module with 2 MHz. VC3 is used to clock
the ADC User Module and is configured for N = 128. The clock source for VC3 is set for VC1.
Other Global Resources.
The SysClk Source must be set to Internal 24 MHz and the SysClk*2
Disable must be set to Yes. The trip voltage is typically set to the lowest value of 2.45 V. LVD Throt-
tleBack must be disabled. The watchdog timer is typically enabled.
