Data Sheet
June 2001
DSP16410B Digital Signal Processor
50
Agere Systems—Proprietary
Use pursuant to Company instructions
Agere Systems Inc.
4 Hardware Architecture
(continued)
4.9 Bit Input/Output Units (BIO
0—1
)
(continued)
Table 17. cbit (BIO Control) Register
If all the IO
0,1
BIT[6:0] pins are configured as outputs
or if the MASK[n] field is cleared for all pins that are
configured as inputs, the BIO
0,1
sets the ALLT and
ALLF flags and clears the SOMET and SOMEF flags.
Table 19 on page 51
summarizes the BIO flags, which
software can test with conditional instructions (see
Table 134 on page 223
). Software can test, save, or
restore the state of the flags by reading or writing the
alf
register (see
Table 140 on page 232
). As illustrated
in
Table 19 on page 51
, ALLT is the logical inverse of
SOMEF and ALLF is the logical inverse of SOMET.
If an IO
0,1
BIT[n] pin is configured as an input and
the software writes
cbit
to change the MASK[n] or
PAT[n] field, there is a latency of two cycles until the
DSP16410B updates the BIO flags to reflect the
change. The following code segment illustrates this
latency by the use of the two
nop
instructions:
sbit=0
cbit=0
...
cbit=0x0302
2*nop
if allt goto OK
// All pins are inputs.
// Test no inputs.
// Test IOBIT[1:0].
// Any 2 instructions.
// Branch if IOBIT1...
// is 1 and IOBIT0 is 0.
15
14—8
7
6—0
Reserved
MODE[6:0]/MASK[6:0]
Reserved
DATA[6:0]/PAT[6:0]
Bit
Field
Value
Description
R/W
Reset
Value
0
0
15
Reserved
MODE[6:0]
(outputs
)
0
0
Reserved—write with zero.
The BIO drives the corresponding IO
0,1
BIT[6:0] output pin to the corre-
sponding value in DATA[6:0].
If the corresponding DATA[6:0] field is 0, the BIO does not change the state
of the corresponding IO
0,1
BIT[6:0] output pin.
If the corresponding DATA[6:0] field is 1, the BIO toggles (inverts) the state
of the corresponding IO
0,1
BIT[6:0] output pin.
The BIO does not test the state of the corresponding IO
0,1
BIT[6:0] input pin
to determine the state of the BIO flags
.
The BIO compares the state of the corresponding IO
0,1
BIT[6:0] input pin to
the corresponding value in the PAT[6:0] field to determine the state of the BIO
flags
—true if pin matches or false if pin doesn’t match.
Reserved—write with zero.
If the corresponding MODE[6:0] field is 0, the BIO drives the corresponding
IO
0,1
BIT[6:0] output pin to logic 0.
If the corresponding MODE[6:0] field is 1, the BIO does not change the
state of the corresponding IO
0,1
BIT[6:0] output pin.
If the corresponding MODE[6:0] field is 0, the BIO drives the corresponding
IO
0,1
BIT[6:0] output pin to logic 1.
If the corresponding MODE[6:0] field is 1, the BIO toggles (inverts) the
state of the corresponding IO
0,1
BIT[6:0] output pin.
If the corresponding MASK[6:0] field is 1, the BIO tests the state of the corre-
sponding IO
0,1
BIT[6:0] input pin to determine the state of the BIO
flags
—true if pin is logic 0 or false if pin is logic 1.
If the corresponding MASK[6:0] field is 1, the BIO tests the state of the corre-
sponding IO
0,1
BIT[6:0] input pin to determine the state of the BIO
flags
—true if pin is logic 1 or false if pin is logic 0.
R/W
R/W
14—8
An IO
0,1
BIT[6:0] pin is configured as an output if the corresponding DIREC[6:0] field (
sbit
[14:8]) has been set by the user software. An
IO
0,1
BIT[6:0] pin is configured as an input if the corresponding DIREC[6:0] field has been cleared by the user software or by device reset.
The BIO flags are ALLT, ALLF, SOMET, and SOMEF. See
Table 19 on page 51
for details on BIO flags.
1
MASK[6:0]
(inputs
)
0
1
7
Reserved
DATA[6:0]
(outputs
)
0
0
R/W
R/W
0
0
6—0
1
PAT[6:0]
(inputs
)
0
1