27.15
External Peripheral Interface (EPI)
Table 27-38. EPI Interface Load Conditions
Load Value (C
L
)
Signals
30 pF
EPI0S[35:0] SDRAM interface
EPI0S[35:0] General-Purpose interface
EPI0S[35:0] Host-Bus interface
40 pF
EPI0S[35:0] PSRAM interface
When the EPI module is in SDRAM mode, EPI CLK must be configured to 12 mA. The EPI data
bus can be configured to 8 mA. Table 27-39 on page 1853 shows the rise and fall times in SDRAM
mode. When the EPI module is in Host-Bus or General-Purpose mode, the values in “Input/Output
Pin Characteristics” on page 1849 should be used.
Table 27-39. EPI SDRAM Characteristics
Unit
Max
Nom
Min
Condition
Parameter Name
Parameter
ns
3
2
-
12-mA drive, C
L
= 30 pF
EPI Rise Time (from 20% to 80% of
V
DD
)
T
SDRAMR
ns
3
2
-
12-mA drive, C
L
= 30 pF
EPI Fall Time (from 80% to 20% of
V
DD
)
T
SDRAMF
Table 27-40. EPI SDRAM Interface Characteristics
a
Unit
Max
Nom
Min
Parameter Name
Parameter
Parameter No
ns
-
-
16.67
SDRAM Clock period
T
CK
E1
ns
-
-
8.33
SDRAM Clock high time
T
CH
E2
ns
-
-
8.33
SDRAM Clock low time
T
CL
E3
ns
4
-
-
CLK to output valid
T
COV
E4
ns
4
-
-
CLK to output invalid
T
COI
E5
ns
4
-
-
CLK to output tristate
T
COT
E6
ns
-
-
8.5
Input set up to CLK
T
S
E7
ns
-
-
0
CLK to input hold
T
H
E8
µs
-
-
100
Power-up time
T
PU
E9
ns
-
-
20
Precharge all banks
T
RP
E10
ns
-
-
66
Auto refresh
T
RFC
E11
EPI CLK
-
-
2
Program mode register
T
MRD
E12
a. The EPI SDRAM interface must use 12-mA drive.
1853
June 18, 2014
Texas Instruments-Production Data
Tiva
™
TM4C1294NCPDT Microcontroller
