Operation Of The Bit Search Module - Fujitsu FR60 Hardware Manual

CHAPTER 11 REALOS-RELATED HARDWARE
11.2.3

Operation of the Bit Search Module

This section describes operation of the bit search module.
■ 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 11.2-1 .
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 11.2-1 .
If a 1 is not found (that is, the value is 00000000
[Execution example]
00100000000000000000000000000000
00000001001000110100010101100111
00000000000000111111111111111111
00000000000000000000000000000001
00000000000000000000000000000000
360
Write data
B
B
B
B
Write data
B
B
B
B
B
), 32 is returned as the search result.
H
Read value (decimal)
(FFFFF000 )
H
(F849E0AA
H
(8002AAAA
H
(FFFFFFFF
H
), 32 is returned as the search result.
H
Read value (decimal)
(20000000
H
(01234567
H
(0003FFFF
H
(00000001
H
(00000000
H
→ 20
→ 5
)
→ 1
)
→ 32
→ 2
)
→ 7
)
→ 14
)
→ 31
)
→ 32
)