Datasheet
IBM PowerPC 750GX RISC Microprocessor
DD1.X
3.6 60x Bus Output AC Specifications
Table 3-9 provides the 60× bus output AC timing specifications for the 750GX as defined in Figure 3-7 on
page 25.
Table 3-9. 60x Bus Output AC Timing Specifications
See Table 3-2 on page 15 for operating conditions.1, 4, 6
Figure 3-7
Timing
Reference
1.8 V
Min.
2.5 V
Min.
3.3 V
Min.
Characteristic
Unit
ns
Notes
Max.
—
Max.
—
Max.
—
SYSCLK to Output Driven
(Output Enable Time)
12
0.3
0.3
0.3
13
14
SYSCLK to Output Valid
—
2.4
—
—
2.3
—
—
2.4
–
ns
ns
5
SYSCLK to Output Invalid (Output Hold)
1.0
0.6
0.6
SYSCLK to Output High Impedance
(all signals except address retry [ARTRY],
address bus busy [ABB], and data bus
busy [DBB])
15
—
—
2.5
—
—
2.5
—
—
2.5
ns
SYSCLK to ABB and DBB high impedance
after precharge
16
17
1.0
3.0
1.0
3.0
1.0
3.0
t
2
3
SYSCLK
SYSCLK to ARTRY high impedance
before precharge
—
—
—
ns
0.2 ×
SYSCLK
0.2 ×
SYSCLK
0.2 ×
SYSCLK
18
SYSCLK to ARTRY precharge enable
t
+
t
+
—
t
+
—
ns
1.0
1.0
1.0
19
20
Maximum delay to ARTRY precharge
—
—
1.0
2.0
—
—
1.0
2.0
—
—
1.0
2.0
t
t
2, 3
2, 3
SYSCLK
SYSCLK to ARTRY high impedance
after precharge
SYSCLK
Notes:
1. All output specifications are measured from the V of the rising edge of SYSCLK to the midpoint of the output signal in question
M
using a test load as shown in Figure 3-6 on page 24. Both input and output timings are measured at the pin. Timings are deter-
mined by design.
2. t
is the period of the external bus clock (SYSCLK) in nanoseconds (ns). The numbers given in the table must be multiplied
SYSCLK
by the period of SYSCLK to compute the actual time duration of the parameter in question.
3. Nominal precharge width for ARTRY is 1.0 t
.
SYSCLK
4. Guaranteed by design and characterization, and not tested.
5. Output Valid timing increases as the V is reduced. These values assume a V minimum of 1.4 V.
DD
DD
6. See Figure 3-6 on page 24 and Figure 3-7 on page 25 for output loading and timing definitions.
750GX_ds_body.fm SA14-2765-02
September 2, 2005
Electrical and Thermal Characteristics
Page 23 of 73
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