UPD78F9222MC(T)-5A4-A NEC, UPD78F9222MC(T)-5A4-A Datasheet - Page 247

• Manufacturer Part Number: UPD78F9222MC(T)-5A4-A
• Description: 8BIT MCU, 4K FLASH, 256B RAM, 78F9222
• Manufacturer: NEC

Specifications of UPD78F9222MC(T)-5A4-A

• Controller Family/series: UPD78
• No. Of I/o's: 17
• Ram Memory Size: 256Byte
• Cpu Speed: 10MHz
• No. Of Timers: 4
• No. Of: RoHS Compliant
• Core Size: 8bit
• Program Memory Size: 4KB
• Oscillator Type: External, Internal

14.1 Register for Confirming Reset Source
store which source has generated the reset request.
Many internal reset generation sources exist in the 78K0S/KA1+. The reset control flag register (RESF) is used to
RESF can be read by an 8-bit memory manipulation instruction.
RESET input, reset input by power-on-clear (POC) circuit, and reading RESF clear RESF to 00H.
The status of RESF when a reset request is generated is shown in Table 14-2.
Address: FF54H
Symbol
RESF
Flag
WDTRF
LVIRF
Note The value after reset varies depending on the reset source.
Caution Do not read data by a 1-bit memory manipulation instruction.
WDTRF
LVIRF
7
0
0
1
0
1
After reset: 00H
Reset Source
Table 14-2. RESF Status When Reset Request Is Generated
Figure 14-5. Format of Reset Control Flag Register (RESF)
Internal reset request is not generated, or RESF is cleared.
Internal reset request is generated.
Internal reset request is not generated, or RESF is cleared.
Internal reset request is generated.
6
0
Note
Cleared (0)
RESET Input
CHAPTER 14 RESET FUNCTION
R
User’s Manual U16898EJ5V0UD
5
0
Internal reset request by low-voltage detector (LVI)
Internal reset request by watchdog timer (WDT)
WDTRF
Cleared (0)
Reset by POC
4
3
0
Set (1)
Held
Reset by WDT
2
0
Held
Set (1)
Reset by LVI
1
0
LVIRF
0
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