Datasheet

Section 9 Timers
Rev. 6.00 Aug 04, 2006 page 330 of 680
REJ09B0145-0600
Mode
Maximum AEVH/AEVL Pin
Input Clock Frequency
16-bit mode
8-bit mode Active (high-speed), sleep (high-speed)
H8/3847R Group
• When not using the internal
step-down circuit
V
CC
= 4.5 to 5.5 V/16 MHz
V
CC
= 2.7 to 5.5 V/10 MHz
V
CC
= 1.8 to 5.5 V/4 MHz
• When using the internal
step-down circuit
V
CC
= 2.7 to 5.5 V/10 MHz
V
CC
= 1.8 to 5.5 V/4 MHz
H8/3847S Group
V
CC
= 2.7 to 3.6 V/10 MHz
V
CC
= 1.8 to 3.6 V/4 MHz
H8/38347 Group
V
CC
= 2.7 to 5.5 V/16 MHz
H8/38447 Group
V
CC
= 4.5 to 5.5 V/16 MHz
V
CC
= 2.7 to 5.5 V/10 MHz
8-bit mode Active (medium-speed), sleep (medium-speed) (φ/16) 2 · f
OSC
(φ/32) f
OSC
(φ/64) 1/2 · f
OSC
f
OSC
= 1 MHz to 16 MHz (φ/128) 1/4 · f
OSC
8-bit mode Watch, subactive, subsleep, standby (φw/2) 1000 kHz
(φw/4) 500 kHz
φ
w
= 32.768 kHz or 38.4 kHz (φw/8) 250 kHz
3. When using the clock in the 16-bit mode, set CUEH to 1 first, then set CRCH to 1 in ECCSR.
Or, set CUEH and CRCH simultaneously before inputting the clock. After that, do not change
the CUEH value while using in the 16-bit mode. Otherwise, an error counter increment may
occur. Also, to reset the counter, clear CRCH and CRCL to 0 simultaneously or clear CRCL
and CRCH to 0 sequentially, in that order.