ATF1500AS-15AC100 ATMEL [ATMEL Corporation], ATF1500AS-15AC100 Datasheet - Page 6

• Manufacturer Part Number: ATF1500AS-15AC100
• Description: High- Performance EE CPLD
• Manufacturer: ATMEL [ATMEL Corporation]

Figure 1. ATF1504AS Macrocell
Programmable Pin-Keeper Option for
Inputs and I/Os
The ATF1504AS offers the option of programming all input
and I/O pins so that pin keeper circuits can be utilized.
When any pin is driven high or low and then subsequently
left floating, it will stay at that previous high or low level.
This circuitry prevents unused input and I/O lines from
floating to intermediate voltage levels, which cause unnec-
essary power consumption and system noise. The keeper
circuits eliminate the need for external pull-up resistors and
eliminate their DC power consumption.
Input Diagram
Speed/Power Management
The ATF1504AS has several built-in speed and power
management features. The ATF1504AS contains circuitry
that automatically puts the device into a low power stand-
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ATF1504ASZ
by mode when no logic transitions are occurring. This not
only reduces power consumption during inactive periods,
but also provides a proportional power savings for most
applications running at system speeds below 50 MHz. This
feature may be selected as a design option.
I/O Diagram
To further reduce power, each ATF1504AS macrocell has
a Reduced Power bit feature. This feature allows individual
macrocells to be configured for maximum power savings.
This feature may be selected as a design option.
All ATF1504ASs also have an optional power down mode.
In this mode, current drops to below 10 mA. When the
power down option is selected, either PD1 or PD2 pins (or
both) can be used to power down the part. The power down
option is selected in the design source file. When enabled,