h8s-2161b Renesas Electronics Corporation., h8s-2161b Datasheet - Page 692

• Manufacturer Part Number: h8s-2161b
• Description: Renesas 16-bit Single-chip Microcomputer H8s Family/h8s/2100 Series
• Manufacturer: Renesas Electronics Corporation.

Section 24 Clock Pulse Generator
24.4
The bus master clock select circuit selects a clock to supply the bus master with either the system
clock ( ) or medium-speed clock ( /2, /4, /8, /16, or /32) by the SCK2 to SCK0 bits in
SBYCR.
24.5
The subclock input circuit controls subclock input from the EXCL pin.
Inputting the Subclock: To use the subclock, a 32.768-kHz external clock should be input from
the EXCL pin. At this time, the P96DDR bit in P9DDR should be cleared to 0, and the EXCLE bit
in LPWRCR should be set to 1.
Subclock input conditions are shown in table 24.5. When the subclock is not used, subclock input
should not be enabled.
Table 24.5 Subclock Input Conditions
Item
Subclock input pulse width
low level
Subclock input pulse width
high level
Subclock input rising time
Subclock input falling time
Rev. 3.00 Mar 21, 2006 page 638 of 788
REJ09B0300-0300
Bus Master Clock Select Circuit
Subclock Input Circuit
EXCL
t
EXCLr
Symbol
t
t
t
t
Figure 24.7 Subclock Input Timing
EXCLL
EXCLH
EXCLr
EXCLf
t
EXCLH
Min
—
—
—
—
Vcc = 2.7 to 5.5 V
Typ
15.26
15.26
—
—
t
EXCLf
t
EXCLL
Max
—
—
10
10
V
Unit
ns
ns
CC
s
s
× 0.5
Measurement
Condition
Figure 24.7