EZ80F920120MOD Zilog, EZ80F920120MOD Datasheet - Page 88

• Manufacturer Part Number: EZ80F920120MOD
• Description: MODULE EZ80F92 512K 20MHZ
• Manufacturer: Zilog

Specifications of EZ80F920120MOD

• Module/board Type: Development Module
• Processor Series: EZ80F92x
• Core: eZ80
• Data Bus Width: 8 bit
• Program Memory Type: Flash
• Program Memory Size: 1 MB
• Interface Type: Cable
• Maximum Clock Frequency: 20 MHz
• Operating Supply Voltage: 0 V to 3.3 V
• Maximum Operating Temperature: + 70 C
• Mounting Style: SMD/SMT
• Package / Case: LQFP
• Development Tools By Supplier: eZ80F920200ZCOG
• Minimum Operating Temperature: 0 C
• For Use With/related Products: eZ80F92
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 269-3157; EZ80F920120MOD

PS015308-0404
Watch-Dog Timer Registers
If the NMI_OUT bit in the WDT_CTL register is set to 1, then upon time-out, the WDT
asserts an NMI for CPU processing. The NMI_FLAG bit can be polled by the CPU to
determine the source of the NMI event.
Watch-Dog Timer Control Register
The Watch-Dog Timer Control register, detailed in Watch-Dog Timer Control Register, is
an 8-bit Read/Write register used to enable the Watch-Dog Timer, set the time-out period,
indicate the source of the most recent RESET, and select the required operation upon
WDT time-out.
Bit
Reset
CPU Access
Note: R = Read only; R/W = Read/Write.
Bit
Position
7
WDT_EN
6
NMI_OUT
5
RST_FLAG*
[4:3]
WDT_CLK
Note: *RST_FLAG is only cleared by a non-WDT RESET.
Value Description
0
1
0
1
0
1
00
01
10
11
Table 27. Watch-Dog Timer Control Register
R/W
WDT is disabled.
WDT is enabled. When enabled, the WDT cannot be disabled
without a
WDT time-out resets the CPU.
WDT time-out generates a nonmaskable interrupt (NMI) to the
CPU.
RESET caused by external full-chip reset or ZDI reset.
RESET caused by WDT time-out. This flag is set by the WDT
time-out, even if the NMI_OUT flag is set to 1. The CPU can
poll this bit to determine the source of the RESET or NMI.
WDT clock source is system clock.
WDT clock source is Real-Time Clock source (32 KHz on-chip
oscillator or 50/60Hz input as set by RTC_CTRL[4]).
Reserved.
Reserved.
P R E L I M I N A R Y
7
0
(WDT_CTL = 0093h)
R/W
6
0
RESET
0/1
.
R
5
R/W
4
0
R/W
3
0
Product Specification
R
2
0
eZ80F92/eZ80F93
Watch-Dog Timer
R/W
1
0
R/W
0
0
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