Texas Instruments TMS320C6745 DSP - EMIFA Timing Requirements for TC5516100 FT-12 Example; ASRAM Timing Requirements for TC5516100 FT-12 Example; Measured PCB Delays for TC5516100 FT-12 Example

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SPRUH91D–March 2013–Revised September 2016
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External Memory Interface A (EMIFA)
18.3.2.2.3 Example Using TC5516100FT-12
This section takes you through the configuration steps required to implement Toshiba’s TC55V1664FT-12
ASRAM with the EMIFA. The following assumptions are made:
• ASRAM is connected to chip select space 3 (EMA_CS[3])
• EMIFA clock speed is 100 MHz (t
cyc
= 10 nS)
Table 18-36 lists the data sheet specifications for the EMIFA and Table 18-37 lists the data sheet
specifications for the ASRAM.
(1)
Depending on operating conditions. See your device-specific data manual for the value.
Table 18-36. EMIFA Timing Requirements for TC5516100FT-12 Example
Parameter Description Min Max Units
t
SU
Data Setup time, data valid before EMA_OE high 3 to 7
(1)
nS
t
H
Data Hold time, data valid after EMA_OE high 0 nS
Table 18-37. ASRAM Timing Requirements for TC5516100FT-12 Example
Parameter Description Min Max Units
t
ACC
Address Access time 12 nS
t
OH
Output data Hold time for address change 3 nS
t
RC
Read cycle time 12 nS
t
WP
Write Pulse width 8 nS
t
AW
Address valid to end of Write 9 nS
t
DS
Data Setup time 7 nS
t
WR
Write Recovery time 0 nS
t
DH
Data Hold time 0 nS
t
WC
Write Cycle time 12 nS
t
COD
Output Disable time from chip enable 7
Table 18-38 lists the values of the PCB board delays. The delays were estimated using the rule that there
is 180 pS of delay for every 1 inch of trace.
Table 18-38. Measured PCB Delays for TC5516100FT-12 Example
Parameter Description Delay (ns)
Read Access
t
EM_CS
Delay on EMA_CS from EMIFA to ASRAM. EMA_CS is driven by EMIF. 0.36
t
EM_A
Delay on EMA_A from EMIFA to ASRAM. EMA_A is driven by EMIF. 0.27
t
EM_OE
Delay on EMA_OE from EMIFA to ASRAM. EMA_OE is driven by EMIF. 0.36
t
EM_D
Delay on EMA_D from ASRAM to EMIFA. EMA_D is driven by ASRAM. 0.45
Write Access
t
EM_CS
Delay on EMA_CS from EMIFA to ASRAM. EMA_CS is driven by EMIF. 0.36
t
EM_A
Delay on EMA_A from EMIFA to ASRAM. EMA_A is driven by EMIF. 0.27
t
EM_WE
Delay on EMA_WE from EMIFA to ASRAM. EMA_WE is driven by EMIF. 0.36
t
EM_D
Delay on EMA_D from EMIFA to ASRAM. EMA_D is driven by EMIF. 0.45