Apparatus and method of orienting asymmetrical semiconductor devices in a circuit

• US 5,748,475 A
• Filed: 05/30/1995
• Issued: 05/05/1998
• Est. Priority Date: 05/30/1995
• Status: Expired due to Term

• Current Assignee: Freescale Semiconductor, Inc. (NXP Semiconductors NV)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Hong, Merit Y.
• Primary Examiner(s): Teska, Kevin J.
• Assistant Examiner(s): McNair, Herbert
• Application Number:
  US08/452,899
• Time in Patent Office: 1,071 Days
• Field of Search: 395/500, 364/488-491, 257/408, 257/344, 257/366, 327/427, 327/437, 327/565, 327/566
• US Class Current: 716/120
• CPC Class Codes: G06F 30/30 Circuit design

Abstract

A computer implemented method provides for orientation and lay-out asymmetrical semiconductor devices. The sources of operating potential (20, 30) are identified. The PMOS transistors (22-28) are combined between the first (more positive) source of operating potential and a common node (12) into a combination block (48). The NMOS transistors (14-18) are combined between the common node and the second (less positive) source of operating potential into another combination block (52). The PMOS source terminals are coupled to more positive potentials, and the PMOS drain terminals are coupled to less positive potentials within the first combination block. The NMOS source terminals are coupled to less positive potentials, and the NMOS drain terminals are coupled to more positive potentials within the second combination block. For transmission gates (60, 62), a driving source is identified and the PMOS and NMOS source terminals are coupled to the driving source.

Claims

1. A computer implemented method of orienting asymmetrical semiconductor devices in an integrated circuit, comprising the steps of:

providing first and second operating potentials where said first operating potential is more positive than said second operating potential;

combining a first type of asymmetrical semiconductor device between said first operating potential and a common node into a first combination block that includes only the first type of asymmetrical semiconductor device;

combining a second type of asymmetrical semiconductor device between said common node and said second operating potential into a second combination block that includes only the second type of asymmetrical semiconductor device;

coupling a source terminal of one of said first type of asymmetrical semiconductor device to a first node operating at a first potential and coupling a drain terminal of said one of said first type of asymmetrical semiconductor device to a second node operating at a second potential less than said first potential in said first combination block; and

coupling a source terminal of one of said second type of asymmetrical semiconductor device to a third node operating at a third potential and coupling a drain terminal of said one of said second type of asymmetrical semiconductor device to a fourth node operating at a fourth potential greater than said third potential in said second combination block.

2. The method of claim 1 wherein said step of combining a first type of asymmetrical semiconductor device includes the step of combining first transistors of said first type of asymmetrical semiconductor device to form a first combination block.

3. The method of claim 2 wherein said step of combining a first type of asymmetrical semiconductor device further includes the step of combining second transistors of said first type of asymmetrical semiconductor device to form a second combination block.

4. The method of claim 3 wherein said step of combining a first type of asymmetrical semiconductor device further includes the step of combining said first and second combination blocks to form an overall combination block of said first type of asymmetrical semiconductor device.

5. The method of claim 4 wherein said step of combining a second type of asymmetrical semiconductor device includes the steps of:

combining first transistors of said second type of asymmetrical semiconductor device to form a third combination block;

combining second transistors of said second type of asymmetrical semiconductor device to form a fourth combination block; and

combining said third and fourth combination blocks to form an overall combination block of said second type of asymmetrical semiconductor device.

6. The method of claim 1 further oriented by the steps including:

identifying a driving source from said first and second combination blocks to a transmission gate that includes asymmetrical PMOS and NMOS transistors;

coupling a source terminal of said asymmetrical PMOS transistor to said driving source and a drain terminal of said asymmetrical PMOS transistor to a receiving node; and

coupling a source terminal of said asymmetrical NMOS transistor to said driving source and a drain terminal of said asymmetrical NMOS transistor to said receiving node.

7. An apparatus for orienting an asymmetrical semiconductor device in an integrated circuit, comprising:

means for providing first and second operating potentials where said first operating potential is more positive than said second operating potential;

means for combining a first type of asymmetrical semiconductor device between said first operating potential and a common node into a first combination block that includes only the first type of asymmetrical semiconductor device;

means for combining a second type of asymmetrical semiconductor device between said common node and said second operating potential into a second combination block that includes only the second type of asymmetrical semiconductor device;

means for coupling a source terminal of one of said first type of asymmetrical semiconductor device to a first node operating at a first potential and coupling a drain terminal of said one of said first type of asymmetrical semiconductor device to a second node operating at a second potential less than said first potential in said first combination block; and

means for a coupling source terminal of one of said second type of asymmetrical semiconductor device to a third node operating at a third potential and coupling a drain terminal of said one of said second type of asymmetrical semiconductor device to a fourth node operating at a fourth potential greater than said third potential in said second combination block.

8. The apparatus of claim 7 further including:

means for identifying a driving source from said first and second combination blocks to a transmission gate that includes asymmetrical PMOS and NMOS transistors;

means for coupling a source terminal of said asymmetrical PMOS transistor to said driving source and a drain terminal of said asymmetrical PMOS transistor to a receiving node; and

means for coupling a source terminal of said asymmetrical NMOS transistor to said driving source and a drain terminal of said asymmetrical NMOS transistor to said receiving node.

9. The apparatus of claim 8 further including:

means for combining first transistors of said first type of asymmetrical semiconductor device to form a first combination block;

means for combining second transistors of said first type of asymmetrical semiconductor device to form a second combination block; and

means for combining said first and second combination blocks to form an overall combination block of said first type of asymmetrical semiconductor device.

10. The apparatus of claim 9 further including:

means for combining first transistors of said second type of asymmetrical semiconductor device to form a third combination block;

means for combining second transistors of said second type of asymmetrical semiconductor device to form a fourth combination block; and

means for combining said third and fourth combination blocks to form an overall combination block of said second type of asymmetrical semiconductor device.

11. An asymmetrical semiconductor device oriented by the steps comprising:

providing first and second operating potentials where said first operating potential is more positive than said second operating potential;

combining a first type of asymmetrical semiconductor device between said first operating potential and a common node into a first combination block that includes only the first type of asymmetrical semiconductor device;

combining a second type of asymmetrical semiconductor device between said common node and said second operating potential into a second combination block that includes only the second type of asymmetrical semiconductor device;

coupling a source terminal of one of said first type of asymmetrical semiconductor device to a first node operating at a first potential and coupling a drain terminal of said one of said first type of asymmetrical semiconductor device to a second node operating at a second potential less than said first potential in said first combination block; and

coupling a source terminal of one of said second type of asymmetrical semiconductor device to a third node operating at a third potential and coupling a drain terminal of said one of said second type of asymmetrical semiconductor device to a fourth node operating at a fourth potential greater than said third potential in said second combination block.

12. The asymmetrical semiconductor device of claim 11 further oriented by the steps including:

identifying a driving source from said first and second combination blocks to a transmission gate that includes asymmetrical PMOS and NMOS transistors;

coupling a source terminal of said asymmetrical PMOS transistor to said driving source and a drain terminal of said asymmetrical PMOS transistor to a receiving node; and

coupling a source terminal of said asymmetrical NMOS transistor to said driving source and a drain terminal of said asymmetrical NMOS transistor to said receiving node.

13. The asymmetrical semiconductor device of claim 12 further oriented by the steps including:

combining a first type of asymmetrical semiconductor includes the step of combining first transistors of said first type of asymmetrical semiconductor device to form a first combination block;

combining a first type of asymmetrical semiconductor further includes the step of combining second transistors of said first type of asymmetrical semiconductor device to form a second combination block; and

combining said first and second combination blocks to form an overall combination block of said first type of asymmetrical semiconductor device.

14. The asymmetrical semiconductor device of claim 13 further oriented by the steps including:

combining first transistors of said second type of asymmetrical semiconductor device to form a third combination block;

combining second transistors of said second type of asymmetrical semiconductor device to form a fourth combination block; and

combining said third and fourth combination blocks to form an overall combination block of said second type of asymmetrical semiconductor device.