Table 13 describes the configuration of the L2_TSTCLK signal to select Fast Out or compatibility
output modes.
Table 13. FastOut/Compatibility Output Signal Configuration
Signal
L2_TSTCLK
Connected to
Mode Selected
Compatibility
Notes
OVdd
GND
FastOut
1
2
HRESET
HRESET
FastOut
Compatibility
Notes:
1. Default Mode
2.HRESET is the inverse state of the HRESET signal
1.8.3 PLL Power Supply Filtering
The AVdd power signal is provided on the 604e to provide power to the clock generation phase-
locked loop. To ensure stability of the internal clock, the power supplied to the AVdd input signal
should be filtered using a circuit similar to the one shown in Figure 11. The circuit should be placed
as close as possible to the AVdd pin to ensure it filters out as much noise as possible.
10 Ω
Vdd
(1.8 V Nom.)
AVdd
10 µF
0.1 µF
GND
Figure 11. PLL Power Supply Filter Circuit
1.8.4 Decoupling Recommendations
Due to the 604e’s large address and data buses, and high operating frequencies, the 604e can
generate transient power surges and high frequency noise in its power supply, especially while
driving large capacitive loads. This noise must be prevented from reaching other components in
the 604e system, and the 604e itself requires a clean, tightly regulated source of power. Therefore,
it is strongly recommended that the system designer place at least one decoupling capacitor with
a low ESR (effective series resistance) rating at each Vdd and OVdd pin of the 604e.
These capacitors should range in value from 220 pF to 10 mF to provide both high- and low-
frequency filtering, and should be placed as close as possible to their associated Vdd pin. Surface-
mount tantalum or ceramic devices are preferred. It is also recommended that these decoupling
capacitors receive their power from Vdd and GND power planes in the PCB, utilizing short traces
to minimize inductance in the traces. Power and ground connections must be made to all external
Vdd and GND pins of the 604e.
1.8.5 Connection Recommendations
To ensure reliable operation, it is recommended to connect unused inputs to an appropriate signal
9/17/99 Revision 1.4
PID9q-604e Hardware Datasheet
23
PRELIMINARY—SUBJECT TO CHANGE WITHOUT NOTICE
IBM [ IBM ]
