HMS87C5216 Datasheet, PDF (70/76 Pages) List of Unclassifed Manufacturers – CMOS SINGLE-CHIP 8-BIT MICROCONTROLLER FOR UR(Universal Remocon) & WIRELESS KEYBOARD

HMS87C5216
18. CLOCK GENERATOR
Clock generating circuit consists of Clock Pulse Generator
(C.P.G), Prescaler, Basic Interval Timer (B.I.T) and Watch Dog
Timer. The clock applied to the Xin pin divided by two is used as
the internal system clock.
fex
OSC
Circuit
fcpu
C.P.G
Internal System Clock
PRESCALER
PS1
ENPCK
8
MUX
0
7
B.I.T (8)
IFBIT
0
5
WDT (6)
WDTCL
3
Peripheral
BTCL
CKCTLR _{0 1 2 3 4 5}
Internal Data Bus
COMPARATOR
WDTON
6
WDTR
6
0
56
IFWDT
To Reset
Circuit
Figure 18-1 Block Diagram of Clock Generator
Prescaler consists of 12-bit binary counter. The clock supplied
from oscillation circuit is input to prescaler (fex). The divided
output from each bit of prescaler is provided to peripheral hard-
ware.
fex
ENPCK
PS1 PS2 PS3 PS4 PS5 PS6 PS7 PS8 PS9 PS10 PS11 PS12
B.I.T
fcpu
PS0 PS1 PS2 PS3 PS4 PS5 PS6 PS7 PS8 PS9 PS10 PS11 PS12
Peripheral
Figure 18-2 Block diagram of Prescaler
SEP. 2004 Ver 1.01