M1AFS600-PQ208 Datasheet, PDF (151/334 Pages) Microsemi Corporation – Fusion Family of Mixed Signal FPGAs

User I/Os
Fusion Family of Mixed Signal FPGAs
Introduction
Fusion devices feature a flexible I/O structure, supporting a range of mixed voltages (1.5 V, 1.8 V, 2.5 V,
and 3.3 V) through a bank-selectable voltage. Table 2-68, Table 2-69, Table 2-70, and Table 2-71 on
page 2-138 show the voltages and the compatible I/O standards. I/Os provide programmable slew rates,
drive strengths, weak pull-up, and weak pull-down circuits. 3.3 V PCI and 3.3 V PCI-X are 5 V–tolerant.
See the "5 V Input Tolerance" section on page 2-147 for possible implementations of 5 V tolerance.
All I/Os are in a known state during power-up, and any power-up sequence is allowed without current
impact. Refer to the "I/O Power-Up and Supply Voltage Thresholds for Power-On Reset (Commercial
and Industrial)" section on page 3-5 for more information. In low power standby or sleep mode (VCC is
OFF, VCC33A is ON, VCCI is ON) or when the resource is not used, digital inputs are tristated, digital
outputs are tristated, and digital bibufs (input/output) are tristated.
I/O Tile
The Fusion I/O tile provides a flexible, programmable structure for implementing a large number of I/O
standards. In addition, the registers available in the I/O tile in selected I/O banks can be used to support
high-performance register inputs and outputs, with register enable if desired (Figure 2-99 on
page 2-136). The registers can also be used to support the JESD-79C DDR standard within the I/O
structure (see the "Double Data Rate (DDR) Support" section on page 2-142 for more information).
As depicted in Figure 2-100 on page 2-141, all I/O registers share one CLR port. The output register and
output enable register share one CLK port. Refer to the "I/O Registers" section on page 2-141 for more
information.
I/O Banks and I/O Standards Compatibility
The digital I/Os are grouped into I/O voltage banks. There are three digital I/O banks on the AFS090 and
AFS250 devices and four digital I/O banks on the AFS600 and AFS1500 devices. Figure 2-113 on
page 2-161 and Figure 2-114 on page 2-162 show the bank configuration by device. The north side of
the I/O in the AFS600 and AFS1500 devices comprises two banks of Pro I/Os. The Pro I/Os support a
wide number of voltage-referenced I/O standards in addition to the multitude of single-ended and
differential I/O standards common throughout all Microsemi digital I/Os. Each I/O voltage bank has
dedicated I/O supply and ground voltages (VCCI/GNDQ for input buffers and VCCI/GND for output
buffers). Because of these dedicated supplies, only I/Os with compatible standards can be assigned to
the same I/O voltage bank. Table 2-69 and Table 2-70 on page 2-137 show the required voltage
compatibility values for each of these voltages.
For more information about I/O and global assignments to I/O banks, refer to the specific pin table of the
device in the "Package Pin Assignments" on page 4-1 and the "User I/O Naming Convention" section on
page 2-161.
Each Pro I/O bank is divided into minibanks. Any user I/O in a VREF minibank (a minibank is the region
of scope of a VREF pin) can be configured as a VREF pin (Figure 2-99 on page 2-136). Only one VREF
pin is needed to control the entire VREF minibank. The location and scope of the VREF minibanks can
be determined by the I/O name. For details, see the "User I/O Naming Convention" section on
page 2-161.
Table 2-70 on page 2-137 shows the I/O standards supported by Fusion devices and the corresponding
voltage levels.
I/O standards are compatible if the following are true:
• Their VCCI values are identical.
• If both of the standards need a VREF, their VREF values must be identical (Pro I/O only).
Revision 4
2- 135