Baud Clock; Real Time Clock; Clock Generation Circuit; Baud Clock Generator - ZiLOG System 8000 Hardware Reference Manual

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LOGIC
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Figure 4-1 Clock Generation Circuit (Sheet 11)
4.2.1. Baud Clock:
The 2.4576 MHz oscillator (U83) is
divided
by
two by U83 and supplies baud rate clock to the
counter-timer circuits (CTCs) for baud generation to the
serial input/output (SIO) circuits. The baud rate clock is
applied directly to the CTCs to produce a programmable baud
rate independent of the system clock rate.
1f!
01---...·
fIAUOCLK
1--.... 1
'""4"
~ W1"a
TO CTC 0.1,2
+2
Figure 4-2 Baud Clock Generator (Sheet 11)
4.2.2.
Real Time Clock: A real time clock is concatenated
from two spare channels in CTC 2 (U89). These channels are
driven by an independent baud rate oscillator so that CTC
programming remains independent of the system clock fre-
quency.
4-3
Zilog 4-3