Z85233 Datasheet, PDF (294/317 Pages) Zilog, Inc. – The Zilog SCC Serial Communication Controller

Application Note
On-Chip Oscillator Design
SUMMARY
1 ^{Understanding the Theory of Operation of oscillators, along with good layout practices, results in a cost effective,}
combined with practical applications, should give trouble free design.Reference the following text for Zilog
designers enough information to design reliable oscillator products with on-chip oscillators and their general/
circuits. Proper selection of crystals and load capacitors, specific requirements.
ZILOG PRODUCT USING ON-CHIP OSCILLATORS
Zilog products that have on-chip oscillators:
Z8^® Family: All
Z80^®: C01, C11, C13, C15, C50, C90, 180, 181, 280
Z8000^®: 8581
Communications Products: SCC_™, ISCC_™, ESCC_™
ZILOG CHIP PARAMETERS
The following are some recommendations on
values/parameters of components for use with Zilog on-
chip oscillators. These are only recommendations; no
guarantees are made by performance of components
outside of Zilog ICs. Finally, the values/parameters chosen
depend on the application. This App Note is meant as a
guideline to making these decisions. Selection of optimal
components is always a function of desired
cost/performance tradeoffs.
Note: All load capacitance specs include stray
capacitance.
Z8 Family
General Requirements:
Crystal Cut: AT cut, parallel resonant, fundamental mode
Crystal Co: < 7 pF for all frequencies.
Crystal Rs: < 100 ohms for all frequencies.
Load Capacitance: 10 to 22 pf, 15 pF typical.
Specific Requirements:
8604: xtal or ceramic, f = 1 - 8 MHz.
8600/10: f = 8 MHz.
8601/03/11/13: f = 12.5 MHz.
8602: xtal or ceramic, f = 4 MHz.
8680/81/82/84/91: f = 8, 12, 16, MHz.
8671: f = 8 MHz.
8612: f = 12, 16 MHz.
86C08/E08: f = 8, 12 MHz.
86C09/19: xtal/resonator, f = 8 MHz, C = 47 pf max.
86C00/10/20/30: f = 8, 12, 16 MHz
86C11/21/91/40/90: f = 12, 16, 20 MHz.
86C27/97: f = 4, 8 MHz.
86C12: f = 12, 16 MHz.
Super8 (all): f = 1 - 20 MHz.
Z8000 Family (8581 only)
General Requirements:
Crystal cut: AT cut, parallel resonant, fundamental mode.
Crystal Co: < 7 pF for all frequencies.
Crystal Rs: < 150 ohms for all frequencies.
Load capacitance: 10 to 33 pF.
Z80 Family
General Requirements:
Crystal cut: AT cut, parallel resonant, fundamental mode.
Crystal Co: < 7 pF for all frequencies.
Crystal Rs: < 60 ohms for all frequencies.
Load capacitance: 10 to 22 pF.
Specific Requirements:
84C01: C1 = 22 pF, C2 = 33 pF (typ); f = DC to 10 MHz.
84C90: DC to 8 MHz.
84C50: same as 84C01.
84C11/13/15: C1 = C2 = 20 -33 pf; f = 6 -10 MHz
80180: f = 12, 16, 20 MHz (Fxtal = 2 x sys. clock).
80280: f = 20 MHz (Fxtal = 2 x Fsysclk).
80181: TBD.
Communications Family
General Requirements:
Crystal cut: AT cut, parallel resonant, fundamental mode.
Crystal Co: < 7 pF for all frequencies.
Crystal Rs: < 150 ohms for all frequencies.
Load capacitance: 20 to 33 pF.
Frequency: cannot exceed PCLK.
Specific Requirements:
8530/85C30/SCC: f = 1 - 6 MHz (10 MHz SCC), 1 - 8.5
MHz (8 MHz SCC).
85130/ESCC (16/20 MHz), f = 1 - 16.384 MHz.
16C35/ISCC: f = 1 -10 MHz.
UM010901-0601
6-159