Specifications

24 EPSON S1C6P466 TECHNICAL MANUAL
CHAPTER 4: PERIPHERAL CIRCUITS AND OPERATION (Oscillation Circuit)
4.3.8 Programming notes
(1) It takes at least 5 msec from the time the OSC3 oscillation circuit goes ON until the oscillation stabi-
lizes. Consequently, when switching the CPU operation clock from OSC1 to OSC3, do this after a
minimum of 5 msec have elapsed since the OSC3 oscillation went ON.
Further, the oscillation stabilization time varies depending on the external oscillator characteristics
and conditions of use, so allow ample margin when setting the wait time.
(2) When switching the clock form OSC3 to OSC1, use a separate instruction for switching the OSC3
oscillation OFF. An error in the CPU operation can result if this processing is performed at the same
time by the one instruction.
(3) In the S1C6P466, the VDC register value does not affect the V
D1 voltage level. However, note that the
CPU clock cannot be switched from OSC1 to OSC3 using the CLKCHG register if the VDC register
value is "0".
When using the S1C6P466 as a development tool for the S1C63454/63458/63466, switch the operating
voltage using the VDC register according to the control sequence of the model (refer to the "Technical
Manual").