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2010 QuickLogic Corporation
QuickLogic PolarPro Device Data Sheet — 86-Pin TFBGA QL1P100
18
Programmable Weak Keeper, Pull-Up, and Pull-Down
A programmable Weak Keeper, Pull-Up or Pull-Down controller is also available on each General Purpose I/O
bank. When implementing the Weak Keeper, Pull-Up, and Pull-Down functions, each I/O can be configured
separately. The I/O Weak Pull-Up and Pull-Down eliminates the need for external resistors. When PBK=1 the
keeper block is placed into keeper mode. In the keeper mode, the pad pin (if the driver is tristated), will be kept
at whichever level it was last forced, either by the driver itself, or by an external driver.
Programmable Drive Strength
Every GPIO has independent drive strength control. Twelve different drive strength levels are available for
designers to choose from. For additional information about corresponding drive strength see DC Programmable Slew Rate
Each I/O has programmable slew rate capability. The PolarPro GPIOs allow up to four different slew rate
speeds (slow, fast, vfast, and wow). Slower slew rates can be used to reduce noise caused by I/O switching.
I/O interface standards are programmable on a per bank basis. Table 19 illustrates the I/O bank
configurations available. Each I/O bank is independent of other I/O banks and each I/O bank has its own
VCCIO supply inputs. A mixture of different I/O standards can be used on a PolarPro device. However, there
is a limitation as to which I/O standards can be supported within a given bank. Only standards that share a
common VCCIO can be shared within the same bank (e.g., PCI and LVTTL).
Table 18: Weak Pull-Up, and Pull-Down Controller
PBK
PBD
PBE
Function
0
Tristate (floating)
0
1
Weak Pull-Down
0
1
Weak Pull-Up
1
X
Weak Keeper (retains state)
0
1
0
Reserved
Table 19: I/O Standards and Applications
I/O Standard
VCCIO Voltage
Application
LVTTL
3.3 V
General Purpose
LVCMOS25
2.5 V
General Purpose
LVCMOS18
1.8 V
General Purpose
PCI
3.3 V
PCI Bus Applications