DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
Information Manual
Instruction Set
April 1998
4-10
DRAFT COPY
Lucent Technologies Inc.
4.4 Processor Flags
(continued)
shows the complete set of flags that can be used in conditional instructions and their meanings. The
state of the four internal flags (defined above) that causes the condition to be true is enclosed in parentheses after
the description. For example, if testing the condition le, the result is true if either the logical minus (LMI) or logical
equal (LEQ) flags are true.
Availability of flags: The BIO and four of the BMU flags (oddp, evenp, nmns1, and mns1) can be read from the alf
register. The LMI, LEQ, LLV, and LMV can be read from the psw register.
Table 4-3. Flags (Conditional Mnemonics)
Test
Meaning
Test
Meaning
pl
Result is nonnegative (not LMI) (
≥
0).
mi
Result is negative (LMI) (< 0).
eq
Result is equal to 0 (LEQ) (= 0).
ne
Result is not equal to 0 (not LEQ) (
≠
0).
gt
Result is greater than 0 (not LMI and
not LEQ) (> 0).
le
Result is less than or equal to 0 (LMI or
LEQ) (
≤
0).
lvs
Logical overflow set (LLV).
lvc
Logical overflow clear (not LLV).
mvs
Mathematical overflow set
(LMV).
mvc
Mathematical overflow clear (not LMV).
c0ge
†
† Testing each of these conditions increments the respective counter being tested.
Counter 0 greater than or equal to 0.
c0lt
Counter 0 less than 0.
c1ge
Counter 1 greater than or equal to 0.
c1lt
Counter 1 less than 0.
heads
‡
‡ The heads or tails condition is determined by a randomly set or cleared bit respectively. The bit is randomly set with probability of
0.5. The random bit is generated by a 10-stage pseudorandom sequence generator (PSG) that is updated after either a heads or
tails test. The pseudorandom sequence can be reset by writing any value to the pi register except during an interrupt service rou-
tine. While in an interrupt service routine, writing to the pi register will update the register and not reset the PSG. If not in an inter-
rupt service routine, writing to the pi register will reset the PSG. (The pi register will be updated but will be written with the
contents of the PC on the next instruction.) Interrupts must be disabled when writing to the pi register. If an interrupt is taken
after the pi write—before pi is updated with the PC value, the ireturn instruction will not return to the correct location. If the RAND
bit in the auc register is set, however, writing the pi register will never reset the PSG. A random rounding function can be imple-
mented with either heads or tails. (For further information, see
Section 5.1.6, DAU Pseudorandom Sequence Generator (PSG)
.)
Pseudorandom sequence bit set.
tails
Pseudorandom sequence bit clear.
true
The condition is always satisfied in an if
instruction.
false
The condition is never satisfied in an if
instruction.
allt
§
§ These flags are only set after an appropriate write to the BIO port (cbit register).
All true—all BIO input bits tested com-
pared successfully.
allf
All false—no BIO input bits tested com-
pared successfully.
somet
Some true—some BIO input bits tested
compared successfully.
Some false—some BIO input bits tested
did not compare successfully.
oddp
Odd parity from BMU operation.
evenp
Even parity from BMU operation.
mns1
Minus 1 result of BMU operation.
nmns1
Not minus 1 result of BMU operation.
npint
Not PINT used by hardware develop-
ment system.
njint
Not JINT used by hardware develop-
ment system.
lock
††
†† DSP1627/28/29 only.
The PLL has achieved lock and is sta-
ble.
ebusy
‡‡
‡‡ DSP1618/28 only.
ECCP busy indicates error correction
coprocessor activity.
Содержание DSP1611
Страница 18: ...Chapter 1 Introduction...
Страница 27: ...Chapter 2 Hardware Architecture...
Страница 52: ...Chapter 3 Software Architecture...
Страница 116: ...Chapter 4 Instruction Set...
Страница 154: ...Chapter 5 Core Architecture...
Страница 176: ...Chapter 6 External Memory Interface...
Страница 208: ...Chapter 7 Serial I O...
Страница 237: ...Chapter 8 Parallel I O DSP1617 Only...
Страница 261: ...Chapter 9 Parallel Host Interface PHIF DSP1611 18 27 28 29 Only...
Страница 275: ...Chapter 10 Bit I O Unit...
Страница 284: ...Chapter 11 JTAG Test Access Port...
Страница 306: ...Chapter 12 Timer...
Страница 313: ...Chapter 13 Bit Manipulation Unit...
Страница 325: ...Chapter 14 Error Correction Coprocessor DSP1618 28 Only...
Страница 350: ...Chapter 15 Interface Guide...
Страница 367: ...Appendix A Instruction Encoding...
Страница 379: ...Appendix B Instruction Set Summary...
Страница 381: ...aD extractz aS IM16 B 52 aD insert aS arM B 53 aD insert aS IM16 B 54 aD aS aaT B 55...
Страница 437: ...Index...