NEC uPD78056Y - Manual (Page 163)

163
CHAPTER 7 CLOCK GENERATOR
The fastest instruction of the
µ
PD78054 and 78054Y Subseries is executed with two clocks of the CPU clock.
Therefore, relationships between the CPU clock (f
CPU
) and the minimum instruction execution time are as shown in
Table 7-2.
Table 7-2. Relationship between CPU Clock and Minimum Instruction Execution Time
CPU Clock (f
CPU
) Minimum Instruction Execution Time: 2/f
CPU
f
X
0.4
µ
s
f X /2 0.8
µ
s
f X /2 2 1.6
µ
s
f X /2 3 3.2
µ
s
f X /2 4 6.4
µ
s
f
X
/2 5 12.8 µ s
f
XT
/2 122
µ
s
Remarks 1. f
X
= 5.0 MHz, f
XT
= 32.768 kHz
2. f X : Main system clock oscillation frequency
3. f XT : Subsystem clock oscillation frequency