MOTOROLA
DSP96002 USER’S MANUAL
2 - 19
ZZ = ^end_of_sequence
v ( ext_acc_req & ^
—
D
—
B
–
G )
(note 3)
ZW = ^ext_acc_req
& ^
—
B
–
G
WX = ^ext_acc_req
&
—
B
–
G
WY = NON-EXISTENT ARC
(note 2)
WZ = ext_acc_req
WW = ^ext_acc_req & ^
—
B
–
G
Notes: 1. Illegal arcs in DSP96002 since once the request of the bus is pending, it will not be canceled
before the execution of the access.
2. Non-existent arc since if ext_acc_req arrives together with the negation of
—
B
–
G, the device
becomes active master and begins its bus transfers.
3.
—
D
—
B
–
G is
—
B
–
G delayed by one phase. This is done to provide a response to the
ext_acc_req signal when it is asserted at the same phase together with
—
B
–
G negation.
5.16.3 Bus Arbitration Example Cases
5.16.3.1 Case 1 – Normal
If the device requesting mastership asserts
—
B
–
R: the arbiter asserts the requesting devices’
—
B
–
G and
—
B
–
B is deasserted indicating the bus is not busy. The requesting device will assert
—
B
–
A.
5.16.3.2 Case 2 – Bus Busy
If the device requesting mastership asserts
—
B
–
R: the arbiter responds by asserting the requesting devic-
es’
—
B
–
G; however, the bus is busy because
—
B
–
B is asserted. The requesting device will not assert
—
B
–
A until
—
B
–
B is deasserted.
5.16.3.3 Case 3 – Low Priority
If the device requesting mastership asserts
—
B
–
R: the arbiter withholds asserting the requesting devices’
—
B
–
G because a higher priority device requested the bus.
—
B
–
A of the requesting device will not be as-
serted.
5.16.3.4 Case 4 – Default
If a device does not request the bus and it is not in the bus parking state but rather it is in the idle state: the
arbiter, by design (i. e., default), asserts
—
B
–
G.
—
B
–
A will remain deasserted.
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 ...
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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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