38K0 Datasheet, PDF (79/133 Pages) Mitsubishi Electric Semiconductor – SINGLE-CHIP 8-BIT CMOS MICROCOMPUTER

38K0 Group
XIN XOUT
Rd (Note)
CIN COUT
Notes : Insert a damping resistor if required.
The resistance will vary depending on the oscillator
and the oscillation drive capacity setting.
Use the value recommended by the maker of the
oscillator.
Also, if the oscillator manufacturer's data sheet
specifies that a feedback resistor be added
external to the chip though a feedback resistor
exists on-chip, insert a feedback resistor between
XIN and XOUT following the instruction.
Fig. 111 Ceramic resonator or quartz-crystal oscilltor circuit
b7
b0
MISRG
(MISRG: address 0FFB16)
Oscillation stabilizing time set after STP instruction
released bit
0: Automatically set “0116” to Timer 1,
“FF16” to Prescaler 12
1: Automatically set nothing
Not used (indefinite at read)
Fig. 113 Structure of MISRG
XIN
XOUT
Open
External oscillation circuit
VCC
VSS
Fig. 112 External clock input circuit
XI N
XOUT
fvco
PLL
USB clock selection bit
fUSB
1/4 1/6 1/8
USB clock division
ration selection bits
fSYN
System clock selection bit
fsio
fAD
1/2 1/2 1/2 1/2
Prescaler 12
1/1 1/2 1/4 1/8
FF16
System clock division
ration selection bits
Timer 1
Reset or STP
0116 ^instruction
Timing φ (internal clock)
QS
SQ
R
STP instruction
WIT
instruction
R
Reset
Interrupt disable flag l
Interrupt request
QS
Reset
R STP instruction
Fig. 114 System clock generating circuit block diagram (single-chip mode)
Rev.3.00 Oct 05, 2006 page 79 of 129
REJ03B0192-0300