Information Manual
DSP1611/17/18/27/28/29 DIGITAL SIGNAL PROCESSOR
April 1998
Instruction Set
Lucent Technologies Inc.
DRAFT COPY
4-7
4.3 Addressing Modes
(continued)
4.3.2 Compound Addressing (continued)
As with other instructions that use the y, a0, and a1 registers, the following rules apply if using the compound
addressing mode:
If clearing of the low half of the register is enabled (according to the CLR field of the auc register), the low half of
the register is cleared when the high half is loaded.
If saturation on overflow is enabled (according to the SAT field of the auc register), the value of data transferred
from the accumulator is limited. (See
Section 5.1, Data Arithmetic Unit
.)
Virtual-shift addressing can be used with compound addressing. The contents of the address register are com-
pared with the contents of register re during both the read and write cycles. If the contents of the address register
are equal to the contents of re during the read cycle and the *rMpz mode is specified, rM is loaded with the con-
tents of rb. If the contents of the address register are equal to the contents of re during the write cycle and the
*rMzp mode is specified, rM is loaded with the contents of rb. Two of the compound addressing formats (*rMm2
and *rMjk) do not work with modulo addressing.
4.3.3 Direct Data Addressing
shows the operation of direct data addressing used in two instructions: DR = *(OFFSET) and
*(OFFSET) = DR. The contents of register DR are read from or written to the RAM memory location at the direct
address. The ybase register holds the base address used for the direct address. It can be loaded with any 16-bit
value, but only the upper 11 bits are used for the address. The ybase register can be thought of as specifying one
of 2048 32-word pages. The OFFSET is a 5-bit address (OFFSET from the ybase register) and is specified in the
opcode. The upper 11 bits of ybase are concatenated with the OFFSET to form the direct address.
The register DR, specified in the opcode by bits 6—9, can be one of a set of 16. They are listed as follows.
Table 4-2. Direct Data Addressing
Register
DR Field
Register
DR Field
r0
0000
y
1000
r1
0001
yl
1001
r2
0010
p
1010
r3
0011
pl
1011
a0
0100
x
1100
a0l
0101
pt
1101
a1
0110
pr
1110
a1l
0111
psw
1111
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...