Dual on-chip and in-package clock distribution system

• US 6,463,547 B1
• Filed: 12/08/1999
• Issued: 10/08/2002
• Est. Priority Date: 12/08/1999
• Status: Expired due to Term

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Compaq Computer Corporation (HP Inc.)
• Inventors: Pickholtz, Jeffrey D., Bell, Shane L., Watson, Jr., Richard B., Bowhill, William J., Bailey, Daniel W.
• Primary Examiner(s): BUTLER, DENNIS
• Application Number:
  US09/457,604
• Time in Patent Office: 1,035 Days
• Field of Search: 713/400, 713/401, 713/500, 713/501, 713/503, 713/600, 716/4, 716/6, 716/10, 716/13, 714/25, 714/30, 714/37, 714/731
• US Class Current: 713/500
• CPC Class Codes: G06F 1/10 Distribution of clock signals , e.g. skew

Abstract

A clock distribution system for a semiconductor device provides for both on-chip and in-package clock distribution via on-chip and in-package clock distribution networks. Each of these networks is selectively enabled depending on the mode of operation. Specifically, for wafer testing, the on-chip clock distribution network is selected. Thus, a probe tester need only provide a single clock source with conventional timing specifications to test the operation of the chip. In contrast, during normal operation, an in-package clock distribution network is enabled. In-package clock routing provides the lowest variation mode and thus, will result in the maximum clock frequency for the chip.

Claims

1. A clock distribution system for a packaged semiconductor device, comprising:

an on-chip clock distribution network for transmitting a clock signal between a clock source and clocked logic;

an in-package clock distribution network for transmitting the clock signal between the clock source and the clocked logic; and

a mode selector for providing the clock signal supplied by either the on-chip clock distribution network or the in-package clock distribution network to the clocked logic.

2. A clock distribution system as claimed in claim 1, wherein the mode selector disables the on-chip distribution network during normal operation of the packaged semiconductor device.

3. A clock distribution system as claimed in claim 1, wherein the mode selector provides only the clock signal received via the in-package clock distribution network to the clocked logic during normal operation of the packaged semiconductor device.

4. A clock distribution system as claimed in claim 1, wherein the mode selector provides only the clock signal received via the on-chip distribution network when the semiconductor device is being tested prior to installation in a package.

5. A clock distribution system as claimed in claim 1, wherein the mode selector provides only the clock signal received via the on-chip distribution network when the semiconductor device is being tested during manufacture.

6. A clock distribution system as claimed in claim 1, wherein the mode selector provides only the clock signal to the clocked logic which has been received via the on-chip distribution network when the semiconductor device is being tested prior to installation in a package and wherein the mode selector provides only the clock signal received via the on-chip distribution network to the clocked logic when the semiconductor device is being tested.

7. A clock distribution system as claimed in claim 1, wherein the mode selector comprises a clock source demultiplexer, which is located near the clock source for the chip, for providing the clock signal on either the on-chip clock distribution network or the in-package clock distribution network.

8. A clock distribution system as claimed in claim 1, wherein the mode selector comprises at least one logic multiplexer, which is located near the clocked logic on the chip, for providing the clock signal from either the on-chip clock distribution network or the in-package clock distribution network to control the clocked logic.

9. A clock distribution system as claimed in claim 1, wherein the mode selector provides only the clock signal received via the on-chip distribution network when the semiconductor device is being tested during manufacture.

10. A clock distribution system as claimed in claim 1, wherein the mode selector comprises:

a clock source demultiplexer, which is located near the clock source for the chip, for providing the clock signal on either the on-chip clock distribution network or the in-package clock distribution network; and

a logic multiplexer, which is located near the clocked logic on the chip, for providing the clock signal from either the on-chip clock distribution network or the in-package clock distribution network to control the clocked logic.

11. A clock distribution system as claimed in claim 1, wherein the mode selector disables the in-package distribution network during testing of the packaged semiconductor device.

12. A clock distribution method for a packaged semiconductor device, the method comprising:

providing for the distribution of a clock signal via an on-chip clock distribution network from a clock source to clocked logic during testing; and

distributing a clock signal via an in-package clock distribution network from a clock source to clocked logic during normal operation.

13. A clock distribution method as claimed in claim 12, further comprising providing a mode selector on the chip for selecting whether the clock signal is supplied by either the on-chip clock distribution network or the in-package clock distribution network to the clocked logic.

14. A clock distribution method as claimed in claim 13, further comprising the mode selector providing only the clock signal received via the in-package clock distribution network during normal operation of the packaged semiconductor device when installed on a printed circuit board to the clocked logic.

15. A clock distribution method as claimed in claim 13, wherein the mode selector provides only the clock signal received via the on-chip distribution network when the semiconductor device is being tested prior to installation in a package.

16. A clock distribution method as claimed in claim 12, wherein the step of distributing a clock signal via the in-package clock distribution network from a clock source to clocked logic during normal operation comprises distributing the clock signal only via the in-package clock distribution network.

17. A clock distribution method as claimed in claim 12, wherein the step of distributing a clock signal via the on-chip clock distribution network from a clock source to the clocked logic during testing comprises distributing the clock signal, which has been provided via a probe tester, to the clocked logic via the on-chip clock distribution network.

18. A clock distribution system for a packaged semiconductor device, comprising:

means for transmitting a clock signal between a clock source and clocked logic on a chip via a chip conducting path present in the chip;

means for transmitting the clock signal between the clock source and the clocked logic via a package conducting path; and

means for providing the clock signal from the chip conducting path or the package conducting path to the clocked logic.

19. A computer system, comprising:

a packaged semiconductor device, including a clock distribution system comprising;

an on-chip clock distribution network for transmitting a clock signal between a clock source and clocked logic,

an in-package clock distribution network for transmitting the clock signal between the clock source and the clocked logic, and

a mode selector for providing the clock signal supplied by either the on-chip clock distribution network or the in-package clock distribution network to the clocked logic; and

a printed circuit board for supporting communications between the semiconductor device and other components of the computer system.