OM13005,598 NXP Semiconductors, OM13005,598 Datasheet - Page 186

• Manufacturer Part Number: OM13005,598
• Description: BOARD EVAL EM773 METER US PLUG
• Manufacturer: NXP Semiconductors
• Type: Other Power Managementr

Specifications of OM13005,598

• Design Resources: Plug Meter Schematics, Gerber Files USB Dongle Schematics, Gerber Files
• Main Purpose: Power Management, Energy/Power Meter
• Embedded: Yes, MCU, 32-Bit
• Utilized Ic / Part: EM773FHN33,551
• Interface Type: USB
• Maximum Operating Temperature: + 150 C
• Operating Supply Voltage: 1.8 V to 3.6 V
• Product: Power Management Development Tools
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Primary Attributes: -
• Secondary Attributes: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• For Use With/related Products: EM773, OL2381
• Other names: 568-6680

NXP Semiconductors
15.7 Example timer calculations
UM10415
User manual
The following example illustrates selecting the SysTick timer reload value to obtain a
10 ms time interval with the EM773 system clock set to 48 MHz.
Example (system clock = 48MHz)
The system tick clock =
RELOAD = (system tick clock frequency × 10 ms) −1 = (24 MHz × 10 ms) −1 = 240000 −1
= 239999 = 0x0003A97F
To use the system tick timer, do the following:
1. Program the SYST_RVR register with the reload value RELOAD to obtain the desired
2. Clear the SYST_CVR register by writing to it. This ensures that the timer will count
3. Program the SYST_SCR register with the value 0x7 which enables the SysTick timer
time interval.
from the SYST_RVR value rather than an arbitrary value when the timer is enabled.
and the SysTick timer interrupt.
All information provided in this document is subject to legal disclaimers.
Rev. 1 — 10 September 2010
system clock
⁄
2
= 24 MHz.
Chapter 15: EM773 System tick timer
UM10415
© NXP B.V. 2010. All rights reserved.
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