Motorola MCF5281 用户手册

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Chapter 11.  Edge Port Module (EPORT)  
11-7
Memory Map and Registers
Table 11-8. EPFR Field Descriptions
Bit(s)
Name
Description
7–1
EPFx
Edge port flag bits. When an EPORT pin is configured for edge triggering, its corresponding 
read/write bit in EPFR indicates that the selected edge has been detected. Reset clears 
EPF7-EPF1.
Bits in this register are set when the selected edge is detected on the corresponding pin. A bit 
remains set until cleared by writing a 1 to it. Writing 0 has no effect. If a pin is configured as 
level-sensitive (EPPARx = 00), pin transitions do not affect this register.
1 Selected edge for IRQx pin has been detected.
0 Selected edge for IRQx pin has not been detected.
0
Reserved, should be cleared.