Bit Search Module Operation - Fujitsu FR60 Hardware Manual

15.3 Bit Search Module Operation

The bit search module performs the following three operations:
• 0 detection
• 1 detection
• Change point detection
■ 0 Detection
The bit search module scans data written to the 0 detection data register from the MSB to LSB
and returns the location where the first "0" is detected. The detection result can be obtained by
reading the detection result register. The relationship between the detected location and the
return value is given in Table 15.3-1.
If a "0" is not found (that is, the value is FFFFFFFF
[Execution example]
11111111111111111111000000000000
11111000010010011110000010101010
10000000000000101010101010101010
11111111111111111111111111111111
■ 1 Detection
The bit search module scans data written to the 1 detection data register from the MSB to LSB
and returns the location where the first "1" is detected. The detection result can be obtained by
reading the detection result register. The relationship between the detected location and the
return value is given in Table 15.3-1.
If a "1" is not found (that is, the value is 00000000
[Execution example]
00100000000000000000000000000000
00000001001000110100010101100111
00000000000000111111111111111111
00000000000000000000000000000001
00000000000000000000000000000000
Write data
Write data
CHAPTER 15 BIT SEARCH MODULE
), 32 is returned as the search result.
H
Read value (decimal)
(FFFFF000 ) --> 20
B H
(F849E0AA ) --> 5
B H
(8002AAAA ) --> 1
B H
(FFFFFFFF ) --> 32
B H
), 32 is returned as the search result.
H
Read value (decimal)
(20000000 ) --> 2
B H
(01234567 ) --> 7
B H
(0003FFFF ) --> 14
B H
(00000001 ) --> 31
B H
(00000000 ) --> 32
B H
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