LM3S5D91 Datasheet, PDF (1263/1340 Pages) Texas Instruments – Stellaris® LM3S5D91 Microcontroller

Stellaris^® LM3S5D91 Microcontroller
25.11
25.12
Input/Output Characteristics
Note: All GPIOs are 5-V tolerant, except PB0 and PB1. See “Signal Description” on page 400 for
more information on GPIO configuration.
Table 25-17. GPIO Module Characteristics
Parameter Parameter Name
Min
Nom
Max
Unit
R_GPIOPU GPIO internal pull-up resistor
100
-
300
kΩ
R_GPIOPD
I_LKG
GPIO internal pull-down resistor
GPIO input leakage current^a
GPIO Rise Time, 2-mA drive^b
200
-
500
kΩ
-
-
2
µA
14
20
ns
T_GPIOR
GPIO Rise Time, 4-mA drive^b
GPIO Rise Time, 8-mA drive^b
7
10
ns
-
4
5
ns
GPIO Rise Time, 8-mA drive with slew rate control^b
6
8
ns
GPIO Fall Time, 2-mA drive^c
14
21
ns
T_GPIOF
GPIO Fall Time, 4-mA drive^c
GPIO Fall Time, 8-mA drive^c
7
11
ns
-
4
6
ns
GPIO Fall Time, 8-mA drive with slew rate control^c
6
8
ns
a. 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.
b. Time measured from 20% to 80% of V_DD.
c. Time measured from 80% to 20% of V_DD.
External Peripheral Interface (EPI)
When the EPI module is in SDRAM mode, the drive strength must be configured to 8 mA. Table
25-18 on page 1263 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 1263 should be used.
Table 25-18. EPI SDRAM Characteristics
Parameter Parameter Name
Condition
Min
T_SDRAMR EPI Rise Time (from 20% to 80% of 8-mA drive, C_L = 16 pF
-
V_DD)
T_SDRAMF
EPI Fall Time (from 80% to 20% of 8-mA drive, C_L = 16 pF
-
V_DD)
Nom
2
2
Max
3
3
Table 25-19. EPI SDRAM Interface Characteristics^a
Parameter No
E1
E2
E3
E4
E5
E6
E7
Parameter
T_CK
T_CH
T_CL
T_COV
T_COI
T_COT
T_S
Parameter Name
SDRAM Clock period
SDRAM Clock high time
SDRAM Clock low time
CLK to output valid
CLK to output invalid
CLK to output tristate
Input set up to CLK
Min
Nom Max
20
-
-
10
-
-
10
-
-
-5
-
5
-5
-
5
-5
-
5
10
-
-
Unit
ns
ns
Unit
ns
ns
ns
ns
ns
ns
ns
January 22, 2012
Texas Instruments-Production Data
1263