TMS32020
SPRS010B— MAY 1987— REVISED NOVEMBER 1990
POST OFFICE BOX 1443 HOUSTON, TEXAS 77001
24
MEMORY AND PERIPHERAL INTERFACE TIMING
switching characteristics over recommended operating conditions (see Note 3)
PARAMETER MIN TYP MAX UNIT
td(C1-S) STRB from CLKOUT1 (if STRB is present) Q – 15 QQ + 15 ns
td(C2-S) CLKOUT2 to STRB (if STRB is present) – 15 0 15 ns
tsu(A) Address setup hold time before STRB low (see Note 5) Q – 30 ns
th(A) Address hold time after STRB high (see Note 5) Q – 15 ns
tw(SL) STRB low pulse duration (no wait states, see Note 6) 2Q ns
tw(SH) STRB high pulse duration (between consecutive cycles, see Note 6) 2Q ns
tsu(D)W Data write setup time before STRB high (no wait states) 2Q – 45 ns
th(D)W Data write hold time from STRB high Q – 15 Q ns
ten(D) Data bus starts being driven after STRB low (write cycle) 0ns
tdis(D) Data bus three-state after STRB high (write cycle) QQ+30
ns
td(MSC) MSC valid from CLKOUT1 –25 0 25 ns
Value derived from characterization data and not tested.
NOTES: 3. Q = 1/4tc(C).
5. A15-A0, PS, DS, IS, R/W, and BR timings are all included in timings referenced as “address”.
6. Delays between CLKOUT1/CLKOUT2 edges and STRB edges track each other, resulting in tw(SL) and tw(SH) being 2Q with
no wait states.
timing requirements over recommended operating conditions (see Note 3)
MIN NOM MAX UNIT
ta(A) Read data access time from address time (read cycle, see Notes 5 and 7) 3Q – 70ns
tsu(D)R Data read setup time before STRB high 40 ns
th(D)R Data read hold time from STRB high 0 ns
td(SL-R) READY valid after STRB low (no wait states) Q – 40 ns
td(C2H-R) READY valid after CLKOUT2 high Q – 40 ns
th(SL-R) READY hold time after STRB low (no wait states) Q – 5 ns
th(C2H-R) READY hold after CLKOUT2 high Q – 5 ns
td(M-R) READY valid after MSC valid 2Q – 50 ns
th(M-R) READY hold time after MSC valid 0 ns
Value derived from characterization data and not tested.
NOTES: 3. Q = 1/4tc(C).
5. A15-A0, PS, DS, IS, R/W, and BR timings are all included in timings referenced as “address”.
7. Read data access time is defined as ta(A) = tsu(A) + tw(SL) – tsu(D)R.
ADVANCE INFORMATION