US38024-BAG1 Renesas Electronics America, US38024-BAG1 Datasheet - Page 124

• Manufacturer Part Number: US38024-BAG1
• Description: DEV EVALUATION KIT H8/38024
• Manufacturer: Renesas Electronics America
• Series: H8®r
• Type: MCUr

Specifications of US38024-BAG1

• Contents: 2G (Second-generation) Evaluation Board, HEW debugger support, Cable and CD-ROM
• For Use With/related Products: H8/38024
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Section 3 Exception Handling
• Example of a malfunction
Rev. 8.00 Mar. 09, 2010 Page 102 of 658
REJ09B0042-0800
When flags are cleared with multiple instructions, other flags might be cleared during
execution of the instructions, even though they are currently set, and this will cause a
malfunction.
Here is an example in which IRRI0 is cleared and disabled in the process of clearing IRRI1
(bit 1 of IRR1).
MOV.B @IRR1:8,R1L ......... IRRI0 = 0 at this time
AND.B #B'11111101,R1L ..... Here, IRRI0 = 1
MOV.B R1L,@IRR1:8 ......... IRRI0 is cleared to 0
In the above example, it is assumed that an IRQ0 interrupt is generated while the AND.B
instruction is executing.
The IRQ0 interrupt is disabled because, although the original objective is clearing IRRI1,
IRRI0 is also cleared.