PALCE29M16H-25 AMD [Advanced Micro Devices], PALCE29M16H-25 Datasheet - Page 20

• Manufacturer Part Number: PALCE29M16H-25
• Description: 24-Pin EE CMOS Programmable Array Logic
• Manufacturer: AMD [Advanced Micro Devices]

OBSERVABILITY
The PALCE29M16 has the capability for product-term
Observability. When the global-Observe product term is
true, the PALCE29M16 will enter the Observe mode.
This feature aids functional testing by allowing direct ob-
servation of register states.
When the PALCE29M16 is in the Observe mode, the
output buffer is enabled and the I/O pin value will be Q of
the corresponding register. This overrides any OE
inputs.
The procedure for Observe is:
2-346
Parameter
Remove the inputs to all the I/O pins.
Symbol
AMD
t
t
I/O
D
Pin 1 (2)
I/O Pins
Input
CLK
Pins
Parameter Description
Delay Time
Valid Output
t
D
Observability Waveform
PALCE29M16H-25
Observe Mode
Because the Observe command is a product term, any
input to the array can be used to set Observe (including
I/O pins and registers). If I/O pins are used, the observe
mode could cause a value change, which would cause
the device to oscillate in and out of the Observe mode.
Therefore, only dedicated input pins should be used for
the Observe command.
Min
100
0.5
Set the inputs to the user selected Observe
configuration.
The register values will be sent to the correspond-
ing I/O pins.
Remove the Observe configuration from the
selected I/O pins.
Rec.
1.0
t
IO
Max
500
5.0
V
V
V
V
V
V
08740G-37
IH
IL
OH
OL
IH
IL
Unit
ns
s