Data Sheet
June 2001
DSP16410B Digital Signal Processor
Agere Systems Inc.
Agere Systems—Proprietary
Use pursuant to Company instructions
245
6 Software Architecture
(continued)
6.2 Registers
(continued)
6.2.3 Register Encodings
(continued)
Table 162. timer0 and timer1 (TIMER
0,1
Running Count) Registers
Table 163. vsw (Viterbi Support Word) Register
15—0
TIMER
0,1
Down Counter
TIMER
0,1
Period Register
Bit
Field
If the user program writes to the
timer
0,1
register, TIMER
0,1
loads the 16-bit write value into the down counter and into the period register
simultaneously. If the user program reads the
timer
0,1
register, TIMER
0,1
returns the current 16-bit value from the down counter.
To read or write the
timer
0,1
register, TIMER
0,1
must be powered up, i.e., the PWR_DWN field (
timer
0,1
c
[6]) must be cleared.
§ For this column, X indicates unknown on powerup reset and unaffected on subsequent reset.
Description
R/W
Reset
Value
§
0
15—0
Down Counter
If the COUNT field (
timer
0,1
c
[4]) is set, TIMER
0,1
decrements this portion
of the
timer
0,1
register every prescale period. When the down counter
reaches zero, TIMER
0,1
generates an interrupt.
Period Register
If the COUNT field (
timer
0,1
c
[4]) and the RELOAD field (
timer
0,1
c
[5]) are
both set and the down counter contains zero, TIMER
0,1
reloads the down
counter with the contents of this portion of the
timer
0,1
register.
R/W
15—0
W
X
15—6
Reserved
5
4
3
2
1
0
VEN
MAX
TB2
Reserved
CFLAG1
CFLAG0
Bit
Field
Value
Description
R/W
Reset
Value
0
0
15—6
5
Reserved
VEN
0
0
1
0
Reserved—write with zero.
Disables Viterbi side effects.
Enables Viterbi side effects.
The
cmp0( )
,
cmp1( )
, and
cmp2( )
functions select the minimum value
from the input operands.
The
cmp0( )
,
cmp1( )
, and
cmp2( )
functions select the maximum
value from the input operands.
For the single-ACS (40-bit)
cmp1( )
function, the traceback encoder
stuffs one traceback bit into
ar0
. For the single-ACS (40-bit)
cmp0( )
function, the traceback encoder stuffs one old traceback bit from
ar0
into
ar1
. For the dual-ACS (16-bit)
cmp1( )
function, the traceback
encoder stuffs CFLAG into
ar0
and
ar2
.
For the single-ACS (40-bit)
cmp1( )
function, the traceback encoder
stuffs two traceback bits into
ar0
. For the single-ACS (40-bit)
cmp0( )
function, the traceback encoder stuffs two old traceback bits from
ar0
into
ar1
.
Reserved—write with zero.
Previous value of CFLAG0. The traceback encoder copies the value of
CFLAG0 to CFLAG1 if the DAU executes a
cmp2( )
function and
VEN=1.
Previous value of CFLAG
. The traceback encoder copies the value of
CFLAG to CFLAG0 if the DAU executes a
cmp2( )
function and
VEN=1.
R/W
R/W
4
MAX
R/W
0
1
3
TB2
0
(GSM/IS95-
compatible
mode)
R/W
0
1
(IS54/IS136-
compatible
mode)
0
—
2
1
Reserved
CFLAG1
R/W
R/W
0
0
0
CFLAG0
—
For the
cmp2(aSE,aDE)
function, CFLAG=0 if MAX=0 and aSE
≥
aDE or if MAX=1 and aSE
<
aDE, and CFLAG=1 if MAX=0 and aSE
<
aDE or if
MAX=1 and aSE
≥
aDE.