
Axcelerator Family FPGAs
2- 16
v2.8
inputs (e.g. INBUF_LVDS) or a pair of differential
outputs (e.g. OUTBUF_LVPECL).
Pull-up and pull-down variations of the INBUF,
BIBUF, and TRIBUF macros. These are available
only with TTL and LVCMOS thresholds. They can
be used to model the behavior of the pull-up and
pull-down resistors available in the architecture.
Whenever an input pin is left unconnected, the
output pin will either go high or low rather than
unknown. This allows users to leave inputs
unconnected without having the negative effect
on simulation of propagating unknowns.
DDR_REG macro. It can be connected to any I/O
standard input buffers (i.e. INBUF) to implement a
double data rate register. Designer software will
map it to the I/O module in the same way it maps
the other registers to the I/O module.
list
all
the
available
macro
names
differentiated by I/O standard, type, slew rate, and drive
strength.
Table 2-15 Macros for Single-Ended I/O Standards
Standard
VCCI
Macro Names
LVTTL
3.3V
CLKBUF, HCLKBUF
INBUF,
OUTBUF,
OUTBUF_S_8, OUTBUF_S_12, OUTBUF_S_16, OUTBUF_S_24,
OUTBUF_H_8, OUTBUF_H_12, OUTBUF_H_16, OUTBUF_H_24,
TRIBUF,
TRIBUF_S_8, TRIBUF_S_12, TRIBUF_S_16, TRIBUF_S_24,
TRIBUF_H_8, TRIBUF_H_12, TRIBUF_H_16, TRIBUF_H_24,
BIBUF,
BIBUF_S_8, BIBUF_S_12, BIBUF_S_16, BIBUF_S_24,
BIBUF_H_8, BIBUF_H_12, BIBUF_H_16, BIBUF_H_24,
3.3V PCI
3.3V
CLKBUF_PCI, HCLKBUF_PCI,
INBUF_PCI,
OUTBUF_PCI,
TRIBUF_PCI,
BIBUF_PCI
3.3V PCI-X
3.3V
CLKBUF_PCI-X,
HCLKBUF_PCI-X,
INBUF_PCI-X,
OUTBUF_PCI-X,
TRIBUF_PCI-X,
BIBUF_PCI-X
LVCMOS25
2.5V
CLKBUF_LVCMOS25,
HCLKBUF_LVCMOS25,
INBUF_LVCMOS25,
OUTBUF_LVCMOS25,
TRIBUF_LVCMOS25,
BIBUF_LVCMOS25
LVCMOS18
1.8V
CLKBUF_LVCMOS18,
HCLKBUF_LVCMOS18,
INBUF_LVCMOS18,
OUTBUF_LVCMOS18,
TRIBUF_LVCMOS18,
BIBUF_LVCMOS18
LVCMOS15 (JESD8-11)
1.5V
CLKBUF_LVCMOS15,
HCLKBUF_LVCMOS15,
INBUF_LVCMOS15,
OUTBUF_LVCMOS15,
TRIBUF_LVCMOS15,
BIBUF_LVCMOS15