EPM7256BUC169-10N Altera, EPM7256BUC169-10N Datasheet - Page 25

• Manufacturer Part Number: EPM7256BUC169-10N
• Description: MAX 7000/S/AE/B
• Manufacturer: Altera

Altera Corporation
Low sustaining current
High sustaining current
Low overdrive current
High overdrive current
Table 12. Bus Hold Parameters
Parameter
V
V
0 V < V
0 V < V
IN
IN
Programmable Pull-Up Resistor
Each MAX 7000B device I/O pin provides an optional programmable
pull-up resistor during user mode. When this feature is enabled for an I/O
pin, the pull-up resistor (typically 50 k¾) weakly holds the output to
V
Bus Hold
Each MAX 7000B device I/O pin provides an optional bus-hold feature.
When this feature is enabled for an I/O pin, the bus-hold circuitry weakly
holds the signal at its last driven state. By holding the last driven state of
the pin until the next input signals is present, the bus-hold feature can
eliminate the need to add external pull-up or pull-down resistors to hold
a signal level when the bus is tri-stated. The bus-hold circuitry also pulls
undriven pins away from the input threshold voltage where noise can
cause unintended high-frequency switching. This feature can be selected
individually for each I/O pin. The bus-hold output will drive no higher
than V
through the input and output buffers in MAX 7000B devices are not
affected by whether the bus-hold feature is enabled or disabled.
The bus-hold circuitry weakly pulls the signal level to the last driven state
through a resistor with a nominal resistance (R
8.5 k¾.
through this resistor and overdrive current that will identify the next
driven input level. This information is provided for each VCCIO voltage
level.
The bus-hold circuitry is active only during user operation. At power-up,
the bus-hold circuit initializes its initial hold value as V
recommended operation conditions. When transitioning from ISP to User
Mode with bus hold enabled, the bus-hold circuit captures the value
present on the pin at the end of programming.
> V
< V
CCIO
Conditions
IL
IH
IN
IN
(max)
(min)
< V
< V
CCIO
level.
Table 12
CCIO
CCIO
to prevent overdriving signals. The propagation delays
gives specific sustaining current that will be driven
Min
–30
30
1.8 V
MAX 7000B Programmable Logic Device Data Sheet
–295
Max
200
VCCIO Level
Min
–50
50
2.5 V
–435
Max
300
BH
Min
–70
70
) of approximately
3.3 V
–680
Max
CC
500
approaches the
Units
μ
μ
μ
μ
A
A
A
A
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