BH67F2470 Datasheet, PDF (62/240 Pages) Holtek Semiconductor Inc – Glucose Meter Flash MCU with LCD

BH67F2470
Glucose Meter Flash MCU with LCD
Operating Mode Switching
The device can switch between operating modes dynamically allowing the user to select the best
performance/power ratio for the present task in hand. In this way microcontroller operations that
do not require high performance can be executed using slower clocks thus requiring less operating
current and prolonging battery life in portable applications.
In simple terms, Mode Switching between the FAST Mode and SLOW Mode is executed using the
CKS2~CKS0 bits in the SCC register while Mode Switching from the FAST/SLOW Mode to the
SLEEP/IDLE Mode is executed via the HALT instruction. When an HALT instruction is executed,
whether the device enters the IDLE Mode or the SLEEP Mode is determined by the condition of the
FHIDEN and FSIDEN bits in the SCC register.
FAST
fSYS=fH~fH/64
fH on
CPU run
fSYS on
fSUB on
SLOW
fSYS=fSUB
fSUB on
CPU run
fSYS on
fH on/off
SLEEP
HALT instruction executed
CPU stop
FHIDEN=0
FSIDEN=0
fH off
fSUB off
IDLE2
HALT instruction executed
CPU stop
FHIDEN=1
FSIDEN=0
fH on
fSUB off
IDLE0
HALT instruction executed
CPU stop
FHIDEN=0
FSIDEN=1
fH off
fSUB on
IDLE1
HALT instruction executed
CPU stop
FHIDEN=1
FSIDEN=1
fH on
fSUB on
Rev. 1.00
62
March 15, 2017