HD6435348R Hitachi Semiconductor, HD6435348R Datasheet - Page 155

• Manufacturer Part Number: HD6435348R
• Description: Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

Input of External Clock Signal
(1) Circuit Configuration (HD6475368R, HD6475348R, HD6435368R, HD6435348R): When
(2) External Clock Input
Frequency
Duty cycle
Note: Mask-ROM versions can operate on external clock input
using an external clock, input complementary clock signals to the EXTAL and XTAL pins as
shown in figure 8-5. Make sure the external clock does not go high during standby mode.
to the EXTAL pin alone, with the XTAL pin left open.
ZTAT
open if the external clock frequency is 16 MHz or less.
Double the system clock (ø) frequency
45% to 55%
versions can also operate with the XTAL pin left
Figure 8-4 Notes on Board Design around External Crystal
Not allowed
C
C
EXTAL
L2
L1
XTAL
Figure 8-5 External Clock Input (Example)
74HC04
Signal A
Fig. 8-5
137
Signal B
External clock input
XTAL
EXTAL
H8/534
H8/536