RCA Spectra 70 - Page 245

Instruction
Op(16)
Subtract
6B
Normalized
(Long)
2B
Subtract
7B
Normalized
(Short)
3B
Subtract
6F
U nnormaIized
(Long)
2F
Subtract
7F
U nnormaIized
(Short)
3F
SUMMARY OF INSTRUCTIONS (Cont/d)
Floating-Point Arithmetic Instructions (Cont'd)
Timing (/Lsed
Mnemonic Format
Interrupt Action
Condition Code (Average and Includes
70/46
SD RX 1. Address error.
o - Result mantissa zero.
27.69
2.
Significance error.
1 - Result mantissa less than
3. Exponent overflow.
zero.
SDR RR
4. Exponent underflow.
2 - Result mantissa greater
22.63
SE RX
than zero.
3 - Result exponent overflow.
19.20
SER
RR
16.08
SW
RX 1. Address error.
o - Result mantissa zero.
26.81
2.
Significance error.
1 - Result mantissa less than
3. Exponent overflow.
zero.
SWR
RR
2 - Result mantissa greater
21.77
than zero.
SU RX
3 - Result exponent overflow.
18.96
SUR RR
15.84
Notes: 1. Time for Ll > L2 and no End Around Carry. Additional time must be added if L2 > Ll
or End Around Carry.
2. If the two fields are equal B = L since all bytes must be examined. If the fields are
unequal the instruction is terminated upon examining the first pair of unequal bytes.
In this case, B is less than L.
3. Each 127 words stored or loaded requires an extra 0.96 microseconds to effect
wrap around.
4. If Debug Mode, 19.20 + EX.
Staticizing)