~ National ~ Semiconductor - Al Kossow's Bitsavers

4.0 Electrical Specifications (Continued)
Latched Read of 1M EM
Symbol 10# Parameter Formula Min Max Units
tSU-RR-CO 1 RAE, REM-RD Falling before ClK-OUT Rising 14 ns
tH-RR-X 2 RAE, REM-RD Rising after XACK Rising 0 ns
tSU-CMD-CO 3 CMD Valid before ClK-OUT Falling 0 ns
tH-CMD-CO 4 CMD Invalid after ClK-OUT Falling 35 ns
tpD-RR-X 5 RAE, REM-RD Falling to XACK Falling 31 ns
tZA-lCl-A 6 A Disabled before lCl Rising 1 ns
tAZ-lCl-A 7 A Enabled before lCl Falling 13 ns
tpD-IMEM-l 8 AD (IMEM) Valid to XACK Rising (nIW+1)T+ -32 ns
tpD-X-IMEM 9 XACK Rising to AD (IMEM) Invalid 0.5T+ -5 ns
tpD-lCl-IA 10 lCl Falling to Next IA Valid (Note 2) T+ -30 0 ns
tW-IMEM 11 IMEMValid (nlW + 1.5)T + -30 ns
Note 1: All parameters are individually tested and guaranteed. Interpreting this data by numerically adding two or more parameters to create a new timing
specification may lead to invalid results.
Note 2: Two remote reads from instruction memory are necessary to read a 16-bit instruction word from IMEM-Iow byte followed by high byte. The timing for the
two reads are the same except that IA is incremented after the high instruction memory byte is read.
elK-OUT
-
RAE
CMD 0n°
Latched Read of IMEM
~~~~=
- 1-0 - CD -
REM-RD ""'"
T
-0-:1
XACK \:
- LCL
~
READ
A
0-1 - -1° -
-®----r-&
AD RIC 1M EM RIC
IA
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r
,-TLiF/9336-70
2-81