Rohm LAPIS SEMICONDUCTOR ML620Q503, User Manual

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ML620Q503/Q504 User's Manual
Chapter 6 Clock Generation Circuit
FEUL620Q504 6–11
6.2.4 Frequency Status Register (FSTAT)
Address: 0F00AH
Access: R
Access size: 8 bits
Initial value: 06H
7 6 5 4 3 2 1 0
FSTAT – – – – – LOSCS HOSCS –
R/W R R R R R R R R
Initial value 0 0 0 0 0 1 1 0
FSTAT is a special function register (SFR) used to show the clock generation circuit state.
Description of Bits
•
HOSCS (bit 1)
HOSCS indicates the oscillation mode of the high-speed oscillator circuit. HOSCS changes when the
high-speed oscillation mode switches.
HOSCS is always "1" if the high-speed built-in RC oscillation mode is selected by the OSCM1 or
OSCM0 bit of the FCON0 register. Regardless of the high-speed oscillation mode, this becomes "1"
when the mode enters the STOP mode, DEEP-HALT mode, HALT-H mode.
HOSCS Description
0 Operating in the high-speed crystal/ceramic oscillation mode or the external clock
input mode
1 •Operating with the high-speed built-in RC oscillator circuit (initial value)
•For the high-speed crystal/ceramic oscillation mode, the high-speed crystal/ceramic
oscillation has stopped or the stabilization time is being counted
•
LOSCS (bit 2)
LOSCS indicates the oscillation mode of the low-speed oscillator circuit. LOSCS changes when the
low-speed oscillation mode switches. LOSCS is always "1" if the low-speed built-in RC oscillation mode
is selected by the XTM1 or XTM0 bit of the FCON2 register. Regardless of the low-speed oscillation
mode, this becomes "1" when the mode enters the STOP mode.
LOSCS Description
0 Operating in the low-speed crystal oscillation mode or the external clock input mode
1 •Operating with the low-speed built-in RC oscillator circuit (initial value)
•For the low-speed crystal oscillation mode, the low-speed crystal oscillation has
stopped or the stabilization time is being counted