Hitachi SH7032 - External Clock Input

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7.2.2 External Clock Input
An external clock signal can be input at the EXTAL pin as shown in figure 7.4. The XTAL pin
should be left open. The frequency must be equal to the system clock (CK) frequency. The
specifications for the waveform of the external clock input are given below. Make the external
clock frequency the same as the system clock (CK).
XTAL
EXTAL
Open
External clock input
Figure 7.4 External Clock Input Method
t
EXr
t
EXf
V
IL
V
IH
1/2 V
cc
t
EXH
t
EXL
t
cyc
Figure 7.5 Input Clock Waveform
Table 7.3 Input Clock Specifications
5 V Specifications
(fmax = 20 MHz)
*
1
3.3 V Specifications
(fmax = 12.5 MHz)
3.3 V Specifications
(fmax = 20 MHz)
*
2
Unit
t
EXr/f
(V
IL
–V
IH
) Max = 5 Max = 10 Max = 5 ns
t
EXH/L
Min = 10 Min = 20 Min = 15 ns
Notes: *1 Except SH7034B
*2 SH7034B only