Reset Sources - Fujitsu FR60 Hardware Manual

CHAPTER 3 CPU AND CONTROL UNITS
3.9.2

Reset Sources

This section describes the reset sources and the reset levels in the MB91350A.
To determine reset sources that have occurred in the past, read the RSRR (reset source
register). (For more information about registers and flags described in this section, see
Section "3.10.5 Block Diagram of Clock Generation Controller" and "3.10.6 Register of
Clock Generation Controller".)
■ INIT Pin Input (Settings Initialization Reset Pin)
The INIT pin, which is an external pin, is used as the settings initialization reset pin.
A settings initialization reset (INIT) request is generated while the "L" level is being input to this pin.
Input the "H" level to this pin to clear a settings initialization reset (INIT) request.
If a settings initialization reset (INIT) is generated in response to a request from this pin, Bit 15 (INIT bit)
of the RSRR (reset source register) is set.
Because a settings initialization reset (INIT) in response to a request from this pin has the highest interrupt
level among all reset sources, it has precedence over any other input, operation, or state.
Immediately after power-on, be sure to apply a settings initialization reset (INIT) at the INIT pin. To assure
the oscillation stabilization wait time for the oscillation circuit immediately after power-on, input the "L"
level to the INIT pin for the stabilization wait time required by the oscillation circuit. INIT at the INIT pin
initializes the oscillation stabilization wait time to the minimum value.
• Reset source: "L" level input to the external INIT pin
• Source of clearing: "H" level input to the external INIT pin
• Reset level: Settings initialization reset (INIT)
• Corresponding flag: Bit 15 (INIT)
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