Cypress CY7C138, CY7C139 CY7C138, CY7C139

CY7C138, CY7C139

Document #: 38-06037 Rev. *D Page 9 of 17

Figure 9. Timing Diagram of Semaphore Contention[27, 28, 29]

Figure 10. Timing Diagram of Read with BUSY (M/S = HIGH)[21]

Switching Waveforms (continued)

tSOP

tAA

SEM

R/W

I/O0

VALID ADDRESS VALID ADDRESS

tHD

DATAINVALID DATAOUTVAL ID

tOHA

A0–A2

tAW

tHA

tACE

tSOP

tSCE

tSD

tSA tPWE

tSWRD tDOE

WRITE CYCLE READ CYCLE

MATCH

tSPS

A0L–A2L

MATCH

R/WL

SEML

A0R–A2R

R/WR

SEMR

Notes

25.Data I/O pins enter high impedance when OE is held LOW during write.

26.CE = HIGH for the duration of the above timing (both write and read cycle).

[+] Feedback

Contents

Main CY7C138, CY7C139 4K x 8/9 Dual-Port Static RAM with Sem, Int, Busy Features Functional Description Logic Block Diagram Pin Configurations Figure 1. 68-Pin PLCC (Top View) Table 2. Selection Guide Description 7C138-15 7C139-15 7C138-25 7C139-25 7C138-35 7C139-35 CY7C138, CY7C139 Maximum Ratings Operating Range Electrical Characteristics Capacitance Page Switching Characteristics Switching Waveforms CY7C138, CY7C139 Document #: 38-06037 Rev. *D Page 7 of 17 Figure 5. Read Timing with Port-to-Port Delay (M/S = L)[20, 21] Figure 6. Write Cycle No. 1: OE Three-States Data I/Os (Either Port)[22, 23, 24] CY7C138, CY7C139 Document #: 38-06037 Rev. *D Page 8 of 17 Figure 7. Write Cycle No. 2: R/W Three-States Data I/Os (Either Port)[22, 24, 25] Figure 8. Semaphore Read After Write Timing, Either Side CY7C138, CY7C139 Figure 9. Timing Diagram of Semaphore Contention[27, 28, 29] Figure 10. Timing Diagram of Read with BUSY (M/S = HIGH)[21] Figure 11. Write Timing with Busy Input (M/S=LOW) Figure 12. Busy Timing Diagram No. 1 (CE Arbitration)[30] Figure 13. Busy Timing Diagram No. 2 (Address Arbitration) CEL Valid Firs t: CER Valid First: Left Address Valid First: Right Address Valid First: Figure 14. Interrupt Timing Diagrams Left Side Sets INTR: Left Side Clears INTL: Right Side Clears INTR: Right Side Sets INTL: CY7C138, CY7C139 Architecture Functional Description Write Operation Read Operation Page Figure 15. Typical DC and AC Characteristics Ordering Information 4K x8 Dual-Port SRAM Package Diagram Document History Page Sales, Solutions and Legal Information Worldwide Sales and Design Support Products PSoC Solutions