
Clocking
Intel® Quark™ SE Microcontroller C1000
Platform Design Guide
June 2017
40
Document Number: 334715-004EN
Table 19. RTC Signals
Signal Name
Direction/Type
Description
OSC32_IN
I Analog
Crystal Input: This signal is connected to
the 32.768 kHz Crystal
OSC32_OUT
O Analog
Crystal Output: This signal is connected to
the 32.768 kHz Crystal
Table 20. RTC Point-to-Point Topology Platform Routing Guidelines
RTC Crystal
OSC32_IN/OSC32_OUT SoC Breakout
Main Routing
Transmission Line
Segment
TL1
TL2
Stackup Layer
(Microstrip/Stripline)
MS/SL
MS/SL
Characteristic
Impedance (SE)
50Ω +/- 10%
50Ω +/- 10%
Trace Width (w)
Meet impedance
Meet impedance
Trace Spacing (S):
to other signals
15 mils
25 mils
Trace Length
< 250 mils
Total Trace Length
Total Length < 1000 mils
Number of vias allowed 2
Via stub length
< 20 mils
Guidelines
Reduce trace capacitance by minimizing the RTC trace length.
Reduce trace signal coupling by avoiding the routing of high speed signals
close to RTC signals.
We highly recommend that you use a ground guard plane.
Do not route RTC as differential signals.
Table 21. 32Mhz Crystal Oscillator specification
Symbol
Parameter
Min.
Typ.
Max.
Unit
Fo
Crystal frequency
32
32
32
Mhz
Cesr
Crystal ESR
12.68
14.41
50
Ω
Cm
Crystal Motional Cap
3.34
3.54
pF
Co
Crystal Shunt Cap
0.84
1.5
pF
CL
Crystal Load Cap
10
pF
Ftol
Frequency Tolerance
-30
30
ppm
Dlev
Drive Level (25Ω)
10
uW