10

MACH211SP-7/10/12/15

V

ANTIS

Bus-Friendly Inputs and I/Os

The MACH211SP inputs and I/Os include two inverters in series which loop back to the input. This

double inversion reinforces the state of the input and pulls the voltage away from the input

threshold voltage. Unlike a pull-up, this configuration cannot cause contention on a bus. For an

illustration of this configuration, please turn to the Input/Output Equivalent Schematics section.

PCI Compliant

The MACH211SP-7/10/12 is fully compliant with the PCI Local Bus Specification published by the

PCI Special Interest Group. The MACH211SP-7/10/12’s predictable timing ensures compliance with

the PCI AC specifications independent of the design.

Power-Down Mode

The MACH211SP features a programmable low-power mode in which individual signal paths can

be programmed as low power. These low-power speed paths will be slightly slower than the

non-low-power paths. This feature allows speed critical paths to run at maximum frequency while

the rest of the paths operate in the low-power mode, resulting in power savings of up to 75%. If

all signals in a PAL block are low-power, then total power is reduced further.

On-Board Programming Options

Since the MACHPRO software performs these steps automatically, the following programming

options are published for reference.

The configuration file, which is also known as the chain file, defines the MACH device JTAG chain.

The file contains the information concerning which JEDEC file is to be placed into which device,

the state which the outputs should be placed, and whether the security fuses should be

programmed. The configuration file is discussed in detail in the MACHPRO software manual.

The MACH211SP devices tristate the outputs during programming. They have one security bit which

inhibits program and verify. This allows the user to protect proprietary patterns and designs.

Program verification of a MACH device involves reading back the programmed pattern and

comparing it with the original JEDEC file. The Vantis method of program verification performed

on the MACH devices permits the verification of one device at a time.

Accidental Programming or Erasure Protection

It is virtually impossible to program or erase a MACH device inadvertently. The following

conditions must be met before programming actually takes place:

x

The device must be in the password-protected program mode

x

The programming or bulk erase instruction must be in the instruction register

If the above conditions are not met, the programming circuitry cannot be activated.