TS80C54X2-LIB View Datasheet(PDF) - Atmel Corporation
Part Name
Description
Manufacturer
TS80C54X2-LIB Datasheet PDF : 58 Pages
| |||
TS80C54X2/C58X2
TS87C54X2/C58X2
10.5 AC Parameters
10.5.1 Explanation of the AC Symbols
Each timing symbol has 5 characters. The first character is always a “T” (stands for time). The other characters,
depending on their positions, stand for the name of a signal or the logical status of that signal. The following is
a list of all the characters and what they stand for.
Example:TAVLL = Time for Address Valid to ALE Low.
TLLPL = Time for ALE Low to PSEN Low.
TA = 0 to +70°C (commercial temperature range); VSS = 0 V; VCC = 5 V ± 10%; -M and -V ranges.
TA = -40°C to +85°C (industrial temperature range); VSS = 0 V; VCC = 5 V ± 10%; -M and -V ranges.
TA = 0 to +70°C (commercial temperature range); VSS = 0 V; 2.7 V < VCC < 5.5 V; -L range.
TA = -40°C to +85°C (industrial temperature range); VSS = 0 V; 2.7 V < VCC < 5.5 V; -L range.
Table 26. gives the maximum applicable load capacitance for Port 0, Port 1, 2 and 3, and ALE and PSEN signals.
Timings will be guaranteed if these capacitances are respected. Higher capacitance values can be used, but timings
will then be degraded.
Port 0
Port 1, 2, 3
ALE / PSEN
Table 26. Load Capacitance versus speed range, in pF
-M
-V
-L
100
50
100
80
50
80
100
30
100
Table 28., Table 31. and Table 34. give the description of each AC symbols.
Table 29., Table 32. and Table 35. give for each range the AC parameter.
Table 30., Table 33. and Table 36. give the frequency derating formula of the AC parameter. To calculate each
AC symbols, take the x value corresponding to the speed grade you need (-M, -V or -L) and replace this value
in the formula. Values of the frequency must be limited to the corresponding speed grade:
Table 27. Max frequency for derating formula regarding the speed grade
Freq (MHz)
T (ns)
-M X1 mode
40
25
-M X2 mode
20
50
-V X1 mode
40
25
-V X2 mode
30
33.3
-L X1 mode
30
33.3
-L X2 mode
20
50
Example:
TLLIV in X2 mode for a -V part at 20 MHz (T = 1/20E6 = 50 ns):
x= 22 (Table 30.)
T= 50ns
TLLIV= 2T - x = 2 x 50 - 22 = 78ns
46
Rev. C - 15 January, 2001
Share Link: 