IEEE 1149.1-COMPLIANT BOUNDARY SCAN TESTABILITY
All MACH 4 devices, except the M4(LV)-128N/64, have boundary scan cells and are compliant
to the IEEE 1149.1 standard. This allows functional testing of the circuit board on which the
device is mounted through a serial scan path that can access all critical logic nodes. Internal
registers are linked internally, allowing test data to be shifted in and loaded directly onto test
nodes, or test node data to be captured and shifted out for veriﬁcation. In addition, these devices
can be linked into a board-level serial scan path for more complete board-level testing.
IEEE 1149.1-COMPLIANT IN-SYSTEM PROGRAMMING
Programming devices in-system provides a number of signiﬁcant beneﬁts including: rapid
prototyping, lower inventory levels, higher quality, and the ability to make in-ﬁeld modiﬁcations.
All MACH 4 devices provide In-System Programming (ISP) capability through their Boundary
ScanTest Access Ports. This capability has been implemented in a manner that ensures that the
port remains compliant to the IEEE 1149.1 standard. By using IEEE 1149.1 as the communication
interface through which ISP is achieved, customers get the beneﬁt of a standard, well-deﬁned
MACH 4 devices can be programmed across the commercial temperature and voltage range.
Vantis provides its free PC-based Lattice/VantisPRO software to facilitate in-system programming.
Lattice/VantisPRO takes the JEDEC ﬁle output produced by Vantis’ design implementation
software, along with information about the JTAG chain, and creates a set of vectors that are used
to drive the JTAG chain. Lattice/VantisPRO software can use these vectors to drive a JTAG chain
via the parallel port of a PC. Alternatively, Lattice/VantisPRO software can output ﬁles in formats
understood by common automated test equipment. This equpment can then be used to program
MACH 4 devices during the testing of a circuit board. For more information about in-system
programming, refer to the separate document entitled MACH ISP Manual.
MACH 4(A) devices in the -5/-55/-6/-65/-7/-10/-12 speed grades are compliant with the PCI
Local Bus Speciﬁcation version 2.1, published by the PCI Special Interest Group (SIG). The 5-V
devices are fully PCI-compliant. The 3.3-V devices are mostly compliant but do not meet the PCI
condition to clamp the inputs as they rise above VCC because of their 5-V input tolerant feature.
SAFE FOR MIXED SUPPLY VOLTAGE SYSTEM DESIGNS
Both the 3.3-V and 5-V VCC MACH 4 devices are safe for mixed supply voltage system designs.
The 5-V devices will not overdrive 3.3-V devices above the output voltage of 3.3 V, while they
accept inputs from other 3.3-V devices. The 3.3-V device will accept inputs up to 5.5 V. Both the
5-V and 3.3-V versions have the same high-speed performance and provide easy-to-use mixed-
voltage design capability.
PULL UP OR BUS-FRIENDLY INPUTS AND I/OS
All MACH 4 devices have inputs and I/Os which feature the Bus-Friendly circuitry incorporating
two inverters in series which loop back to the input. This double inversion weakly holds the
input at its last driven logic state. While it is good design practice to tie unused pins to a known
state, the Bus-Friendly input structure pulls pins away from the input threshold voltage where
noise can cause high-frequency switching. At power-up, the Bus-Friendly latches are reset to a
MACH 4 Family