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DSP96002 USER’S MANUAL
MOTOROLA
When a bus master, the combination of
—
B
–
S and
—
T
–
S can be decoded externally to
determine the status of the current bus cycle and to generate hardware strobes useful
for latching address and data signals. The encoding is shown in Figure 2-4.
—
T
–
A
(Transfer Acknowledge) - active low input. If the DSP96002 is the bus master and either
there is no external bus activity or the DSP96002 is not the bus master, the
—
T
––
A input
is ignored by the core. The
—
T
–
A input is a synchronous "DTACK" function which can
extend an external bus cycle indefinitely.
—
T
–
A must be asserted and deasserted syn-
chronous to the input clock (CLK) for proper operation.
—
T
–
A is sampled on the falling
edge of the input clock (CLK). Any number of wait states (0, 1, 2, ..., infinity) may be
inserted by keeping
—
T
–
A deasserted. In typical operation,
—
T
–
A is deasserted at the
start of a bus cycle, is asserted to enable completion of the bus cycle and is deasserted
before the next bus cycle. The current bus cycle completes one clock period after
—
T
–
A is asserted synchronous to CLK. The number of wait states is determined by the
—
T
–
A input or by the Bus Control Register (BCR), whichever is longer. The BCR can be
used to set the minimum number of wait states in external bus cycles. If
—
T
–
A is tied
low (asserted) and no wait states are specified in the BCR register, zero wait states will
be inserted into external bus cycles.
Figure 2-4. Bus Status Encoding
—
B
–
S
—
T
–
S Bus Status
Strobe Generation Application
1
1
Idle
0
1
Cycle Start
Address Strobe (
—
A
–
S)
0
0
Wait
1
0
Cycle End
Data Strobe (
—
D
–
S)
t0
t1
t2
t3
t0
t1
t2
tw
t2
tw
t2
t3
CLK
—
B
–
—
T
–
S
—
D
–
—
A
–
WS
WS
Summary of Contents for DSP96002
Page 3: ...1 2 DSP96002 USER S MANUAL MOTOROLA ...
Page 38: ...MOTOROLA DSP96002 USER S MANUAL 3 15 Figure 3 4 Modulo Arithmetic Unit Block Diagram ...
Page 39: ...3 16 DSP96002 USER S MANUAL MOTOROLA ...
Page 53: ...4 14 DSP96002 USER S MANUAL MOTOROLA ...
Page 76: ...MOTOROLA DSP96002 USER S MANUAL 5 23 Figure 5 8 Address Modifier Summary ...
Page 86: ...6 10 DSP96002 USER S MANUAL MOTOROLA ...
Page 101: ...MOTOROLA DSP96002 USER S MANUAL 7 15 Figure 7 9 HI Block Diagram One Port ...
Page 140: ...7 54 DSP96002 USER S MANUAL MOTOROLA ...
Page 166: ...9 10 DSP96002 USER S MANUAL MOTOROLA ...
Page 181: ...MOTOROLA DSP96002 USER S MANUAL 10 15 Figure 10 8 Program Address Bus FIFO ...
Page 337: ...MOTOROLA DSP96002 USER S MANUAL A 149 ...
Page 404: ...A 216 DSP96002 USER S MANUAL MOTOROLA PC xxxx D ...
Page 460: ...A 272 DSP96002 USER S MANUAL MOTOROLA SIOP Not affected ...
Page 484: ...A 296 DSP96002 USER S MANUAL MOTOROLA SSH PC SSL SR SP 1 SP ...
Page 519: ...MOTOROLA DSP96002 USER S MANUAL A 331 ...
Page 718: ...MOTOROLA DSP96002 USER S MANUAL B 199 ...
Page 871: ... MOTOROLA INC 1994 MOTOROLA TECHNICAL DATA SEMICONDUCTOR M Addendum ...
Page 888: ...MOTOROLA INDEX 1 INDEX ...
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