1. Pin Configurations
Table 1-1. Pin Descriptions
Three-state DATA Output for Configuration. Open-collector bi-directional pin for programming.
Clock Input. Used to increment the internal address and bit counter for reading and programming.
Enable Page Download Mode Input. When PAGE_EN is high the configuration download address
space is partitioned into four equal pages. This gives users the ability to easily store and retrieve
multiple configuration bitstreams from a single configuration device. This input works in conjunction
with the PAGESEL inputs. PAGE_EN must be remain low if paging is not desired. When SER_EN is
Low (ISP mode) this pin has no effect.
Page Select Input. Used to determine which of the four memory pages are targeted during a serial
configuration download. The address space for each of the pages is shown in Table 1-2. When
SER_EN is Low (ISP mode) these pins have no effect.
Output Enable (Active High) and RESET (Active Low) when SER_EN is High. A Low level on
RESET/OE resets both the address and bit counters. A High level (with CE Low) enables the data
Chip Enable Input (Active Low). A Low level (with OE High) allows CLK to increment the address
counter and enables the data output driver. A High level on CE disables both the address and bit
counters and forces the device into a low-power standby mode. Note that this pin will not
enable/disable the device in the 2-wire Serial Programming mode (SER_EN Low).
Ground. A 0.2μF decoupling capacitor between VCC and GND is recommended.
Chip Enable Output (when SER_EN is High). This output goes Low when the internal address
counter has reached its maximum value. If the PAGE_EN input is set High, the maximum value is the
highest address in the selected partition. The PAGESEL[1:0] inputs are used to make the four
partition selections. If the PAGE_EN input is set Low, the device is not partitioned and the address
maximum value is the highest address in the device (Table 1-2). In a daisy chain of AT17F Series
devices, the CEO pin of one device must be connected to the CE input of the next device in the chain.
It will stay Low as long as CE is Low and OE is High. It will then follow CE until OE goes Low;
thereafter, CEO will stay High until the entire EEPROM is read again.
Device Selection Input, (when SER_EN Low). The input is used to enable (or chip select) the
device during programming (i.e., when SER_EN is Low). Refer to the Atmel AT17F Programming
Specification available on the Atmel web site for additional details.
Open Collector Reset State Indicator. Driven Low during power-up reset, released when power-up
is complete. (recommended 4.7k pull-up on this pin if used).
Serial Enable Input. Must remain High during FPGA configuration operations. Bringing SER_EN
Low enables the 2-Wire Serial Programming Mode. For non-ISP applications, SER_EN should be
tied to VCC.
Device Power Supply. +3.3V (±10%)
Notes: 1. Internal 20K pull-up resistor
2. Internal 30K pull-up resistor
2 AT17F040/080 [DATASHEET]