Z51F3220FNX Datasheet, PDF (286/312 Pages) Zilog, Inc. – Z8051 Series 8-Bit Microcontrollers

Z51F3220
Product Specification
13.8.1 Register Map
Table 13-3 Reset Operation Register Map
Name
Address
Dir
RSTFR
E8H
R/W
LVRCR
D8H
R/W
LVICR
86H
R/W
Default
80H
00H
00H
Description
Reset Flag Register
Low Voltage Reset Control Register
Low Voltage Indicator Control Register
13.8.2 Reset Operation Register Description
The reset control register consists of the reset flag register (RSTFR), low voltage reset control register (LVRCR),
and low voltage indicator control register (LVICR).
13.8.3 Register Description for Reset Operation
RSTFR (Reset Flag Register) : E8H
7
6
5
4
3
2
PORF
EXTRF
WDTRF
OCDRF
LVRF
–
R/W
R/W
R/W
R/W
R/W
–
1
0
–
–
–
–
Initial value : 80H
PORF
EXTRF
WDTRF
OCDRF
LVRF
Power-On Reset flag bit. The bit is reset by writing ‘0’ to this bit.
0
No detection
1
Detection
External Reset (RESETB) flag bit. The bit is reset by writing ‘0’ to this bit
or by Power-On Reset.
0
No detection
1
Detection
Watch Dog Reset flag bit. The bit is reset by writing ‘0’ to this bit or by
Power-On Reset.
0
No detection
1
Detection
On-Chip Debug Reset flag bit. The bit is reset by writing ‘0’ to this bit or by
Power-On Reset.
0
No detection
1
Detection
Low Voltage Reset flag bit. The bit is reset by writing ‘0’ to this bit or by
Power-On Reset.
0
No detection
1
Detection
NOTES) 1. When the Power-On Reset occurs, the PORF bit is only set to “1”, the other flag (WDTRF and
OCDRF) bits are all cleared to “0”.
2. When the Power-On Reset occurs, the EXTRF bit is unknown, At that time, the EXTRF bit can be set
to “1” when External Reset (RESETB) occurs.
3. When the Power-On Reset occurs, the LVRF bit is unknown, At that time, the LVRF bit can be set to
“1” when LVR Reset occurs.
4. When a reset except the POR occurs, the corresponding flag bit is only set to “1”, the other flag bits
are kept in the previous values.
PS029902-0212
PRELIMINARY
284