Apparatus and method for controlling memory overrun

1. A method for transacting data with an addressable memory, comprising:

receiving a target address value of a requested memory transaction;

determining whether the target address value is greater than a maximum legacy address value;

in response to a determination that the target address value is greater than the maximum legacy address value, emulating a legacy-memory transaction by performing an emulation of a selectable type, wherein the emulation of the selectable type is selectable from between: (a) inhibiting the requested memory transaction; and (b) allowing the requested memory transaction at the maximum legacy address value; and

in response to a determination that the target address value is not greater than the maximum legacy address value, executing a standard memory transaction.

2. The method of claim 1 , wherein the emulation of the selectable type comprises inhibiting the requested memory transaction.

3. The method of claim 1 , wherein the emulation of the selectable type comprises allowing the requested memory transaction at the maximum legacy address value.

4. The method of claim 1 , wherein the requested memory transaction comprises reading data from the addressable memory.

5. The method of claim 1 , wherein the requested memory transaction comprises writing data to the addressable memory.

6. The method of claim 1 , wherein the maximum legacy address value is selectable.

7. A memory-address filter, comprising:

an input adapted to receive a target address value of a requested memory transaction;

an output in communication with an addressable memory; and

a legacy-memory emulator in communication with the input and the output, the legacy-memory emulator configured to:

emulate a legacy memory transaction in response to the target address value being greater than a maximum legacy address value, and

perform a standard memory transaction if the target address value is not greater than the maximum legacy address value

wherein the legacy-memory emulator comprises a mode-selector, and wherein the legacy memory transaction is of a type selectable, using the mode-selector, between: (a) inhibiting the requested memory transaction; and (b) allowing the requested memory transaction at the maximum legacy address value.

8. The memory-address filter of claim 7 , wherein the legacy-memory emulator comprises a comparator circuit determining whether the target address value is greater than the maximum legacy address value.

9. The memory-address filter of claim 7 , further comprising a storage element configured to store the maximum legacy address value.

10. The memory-address filter of claim 7 , wherein the mode selector comprises at least one mode selection register storing at least one of a STOP value and a memory overrun enable value.

11. The memory-address filter of claim 7 , wherein the legacy memory emulator comprises a strobe inhibitor, configured to inhibit a requested write memory transaction in response to the received target address value being greater than the maximum legacy address value.

12. A memory-address filter, comprising:

means for receiving a target address value of a requested memory transaction;

means for determining whether the target address value is greater than a maximum legacy address value;

means for, in response to a determination that the target address value is greater than the maximum legacy address value, performing a legacy memory transaction of a type selectable between: (a) inhibiting the requested memory transaction; and (b) allowing the requested memory transaction at the maximum legacy address value; and

means for providing the target address value to an addressable memory, in response to a determination that the target address value is not greater than the maximum legacy address value.

13. A system comprising:

automatic test equipment configured to couple to a device under test (DUT) and to execute a test program to perform a test of the DUT, the automatic test equipment comprising the memory-address filter of claim 7 .

14. An automatic test system, comprising:

automatic test equipment (ATE) configured to couple to a device under test (DUT) and to execute a test program to perform a test of the DUT, the ATE comprising:

an input adapted to receive a target ATE memory address value of a requested ATE memory transaction, the target ATE memory address value identifying a target ATE memory address value of an addressable memory of the ATE;

an output in communication with the, addressable memory; and

a legacy-memory emulator in communication with the input of the ATE and the output of the ATE, the legacy-memory emulator configured to:

emulate a legacy ATE memory transaction in response to the target ATE memory address value being greater than a maximum ATE legacy address value, and

perform a standard ATE memory transaction if the target ATE memory address value of the memory of the ATE is not greater than the maximum ATE legacy address value,

wherein the legacy-memory emulator comprises a mode-selector, and wherein the legacy ATE memory transaction is of a type selectable, using the mode-selector, from among a plurality of types of legacy ATE memory transactions.

15. The automatic test system of claim 14 , wherein the legacy ATE memory transaction is of a type selectable between: (a) inhibiting the requested ATE memory transaction; (b) allowing the requested ATE memory transaction at the maximum ATE legacy address value; and (c) allowing the requested ATE memory transaction at an overrun-adjusted ATE address value determined by a wrapping of the target ATE address value with respect to the maximum ATE legacy address value.

16. The automatic test system of claim 15 , wherein the legacy ATE memory transaction is of a type selectable between: (a) inhibiting the requested ATE memory transaction; and (b) allowing the requested ATE memory transaction at the maximum ATE legacy address value.