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LM3S5G31 Datasheet, PDF (1156/1223 Pages) Texas Instruments – Stellaris LM3S5G31 Microcontroller
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Electrical Characteristics
25.13
Table 25-21. GPIO Module Characteristics (continued)
Parameter Parameter Name
Min
Nom
Max
GPIO rise time, 2-mA drivec
14
20
TGPIOR
GPIO rise time, 4-mA drivec
GPIO rise time, 8-mA drivec
7
10
-
4
5
GPIO rise time, 8-mA drive with slew rate controlc
6
8
GPIO fall time, 2-mA drived
14
21
TGPIOF
GPIO fall time, 4-mA drived
GPIO fall time, 8-mA drived
7
11
-
4
6
GPIO fall time, 8-mA drive with slew rate controld
6
8
Unit
ns
ns
ns
ns
ns
ns
ns
ns
a. VDD must be within the range specified in Table 25-2 on page 1145.
b. The leakage current is measured with GND or VDD applied to the corresponding pin(s). The leakage of digital port pins is
measured individually. The port pin is configured as an input and the pullup/pulldown resistor is disabled.
c. Time measured from 20% to 80% of VDD.
d. Time measured from 80% to 20% of VDD.
External Peripheral Interface (EPI)
When the EPI module is in SDRAM mode, the drive strength must be configured to 8 mA. Table
25-22 on page 1156 shows the rise and fall times in SDRAM mode with 16 pF load conditions. When
the EPI module is in Host-Bus or General-Purpose mode, the values in “Input/Output
Characteristics” on page 1155 should be used.
Table 25-22. EPI SDRAM Characteristics
Parameter Parameter Name
Condition
Min
TSDRAMR EPI Rise Time (from 20% to 80% of 8-mA drive, CL = 16 pF
-
VDD)
TSDRAMF
EPI Fall Time (from 80% to 20% of 8-mA drive, CL = 16 pF
-
VDD)
Nom
2
2
Max
3
3
Table 25-23. EPI SDRAM Interface Characteristicsa
Parameter No Parameter
Parameter Name
E1
TCK
SDRAM Clock period
E2
TCH
SDRAM Clock high time
E3
TCL
SDRAM Clock low time
E4
TCOV
CLK to output valid
E5
TCOI
CLK to output invalid
E6
TCOT
CLK to output tristate
E7
TS
Input set up to CLK
E8
TH
CLK to input hold
E9
TPU
Power-up time
E10
TRP
Precharge all banks
E11
TRFC
Auto refresh
E12
TMRD
Program mode register
a. The EPI SDRAM interface must use 8-mA drive.
Min
Nom Max
20
-
-
10
-
-
10
-
-
-5
-
5
-5
-
5
-5
-
5
10
-
-
0
-
-
100
-
-
20
-
-
66
-
-
40
-
-
Unit
ns
ns
Unit
ns
ns
ns
ns
ns
ns
ns
ns
µs
ns
ns
ns
1156
Texas Instruments-Production Data
July 03, 2014
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