UPD78F0890GK(A)-GAJ-AX NEC, UPD78F0890GK(A)-GAJ-AX Datasheet - Page 129

• Manufacturer Part Number: UPD78F0890GK(A)-GAJ-AX
• Description: 8BIT MCU, 128K FLASH, 7K RAM, LQFP
• Manufacturer: NEC

Specifications of UPD78F0890GK(A)-GAJ-AX

• Controller Family/series: UPD78F
• No. Of I/o's: 55
• Ram Memory Size: 7KB
• Cpu Speed: 20MHz
• No. Of Timers: 10
• No. Of Pwm: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 128KB
• Oscillator Type: External, Internal

Note The main clock mode register (MCM) is used to set the CPU clock (high-speed system clock/internal high-
The fastest instruction can be executed in 2 clocks of the CPU clock in the 78K0/FE2. Therefore, the relationship
between the CPU clock (f
f
f
f
f
f
f
Address: FFFBH
XP
XP
XP
XP
XP
SUB
Symbol
CPU Clock (f
/2
/2
/2
/2
/2
PCC
2
3
4
speed oscillation clock) (see Figure 6-4).
Table 6-2. Relationship Between CPU Clock and Minimum Instruction Execution Time
Caution
Notes 1. Bit 5 is read-only.
Remarks 1. f
CPU
CSS
CLS
)
7
0
0
1
0
1
Note 2
After reset: 01H
2. Be sure to switch CSS from 1 to 0 when bits 1 (MCS) and 0 (MCM0) of the main clock
Figure 6-2. Format of Processor Clock Control Register (PCC)
0.2
0.4
0.8
1.6
3.2
High-Speed System Clock
2. f
mode register (MCM) are 1.
Be sure to clear bits 3 and 6 to 0.
At 10 MHz
Operation
μ
μ
μ
μ
μ
Main system clock
Subsystem clock
CPU
s
s
s
s
s
XP
SUB
PCC2
Other than above
) and the minimum instruction execution time is as shown in Table 6-2.
:
6
0
0
0
0
0
1
0
0
0
0
1
: Subsystem clock frequency
Main system clock oscillation frequency
−
0.1
0.2
0.4
0.8
1.6
R/W
CHAPTER 6 CLOCK GENERATOR
At 20 MHz
Operation
PCC1
μ
μ
μ
μ
μ
CLS
<5>
Note 1
s
s
s
s
s
User’s Manual U17554EJ4V0UD
0
0
1
1
0
0
0
1
1
0
Minimum Instruction Execution Time: 2/f
Note
0.25
0.5
1.0
2.0
4.0
PCC0
CSS
<4>
At 8 MHz (TYP.) Operation
0
1
0
1
0
0
1
0
1
0
μ
μ
μ
μ
μ
s (TYP.)
s (TYP.)
s (TYP.)
s (TYP.)
Internal high-speed
Oscillator Clock
s (TYP.)
CPU clock status
f
f
f
f
f
f
Setting prohibited
XP
XP
XP
XP
XP
SUB
/2 (default)
/2
/2
/2
−
/2
2
3
4
3
0
Note
CPU clock (f
PCC2
2
122.1
CPU
At 32.768 kHz Operation
CPU
μ
Subsystem Clock
) selection
s
PCC1
1
−
−
−
−
−
PCC0
0
129