Rainbow Electronics AT75C220 - Manual (Page 141)

AT75C220
141
WD Overflow Mode Register
Name: WD_OMR
Access: Read/write
Reset Value:0
• WDEN: Watchdog Enable
0 = Watchdog is disabled and does not generate any signals.
1 = Watchdog is enabled and generates enabled signals.
• RSTEN: Reset Enable
0 = Generation of an internal reset by the watchdog is disabled.
1 = When overflow occurs, the watchdog generates an internal reset.
• IRQEN: Interrupt Enable
0 = Generation of an interrupt by the watchdog is disabled.
1 = When overflow occurs, the watchdog generates an interrupt.
• EXTEN: External Signal Enable
0 = Generation of a pulse on the pin NWDOVF by the watchdog is disabled.
1 = When an overflow occurs, a pulse on the pin NWDOVF is generated.
• OKEY: Overflow Access Key
Used only when writing WD_OMR. OKEY is read as 0.
0x234 = Write access in WD_OMR is allowed.
Other value = Write access in WD_OMR is prohibited.
31 30 29 28 27 26 25 24
– – – – – – – –
23 22 21 20 19 18 17 16
– – – – – – – –
15 14 13 12 11 10 9 8
OKEY
7 6 5 4 3 2 1 0
OKEY EXTEN IRQEN RSTEN WDEN