Arbitration Timings - Motorola DSP56367 User Manual

3.10.3

ARBITRATION TIMINGS

Table 3-17 Asynchronous Bus Arbitration Timing
No.
250 BB assertion window from BG input
negation.
251 Delay from BB assertion to BG assertion
Note: 1.
2.
3.
BG1
BB
BG2
Figure 3-18 Asynchronous Bus Arbitration Timing
MOTOROLA
Characteristics
Bit 13 in the OMR register must be set to enter Asynchronous
Arbitration mode
If Asynchronous Arbitration mode is active, none of the timings in
Table 3-17 is required.
In order to guarantee timings 250, and 251, it is recommended to
assert BG inputs to different 56300 devices (on the same bus) in a non
overlap manner as shown in Figure 3-18.
DSP56367
External Memory Expansion Port (Port A)
120 MHz
Expression
Min
2 .5* Tc + 5 —
2 * Tc + 5 21.7
250
251
Specifications
Un
it
Max
25.8 ns
— ns
3-45