Product preview – Texas Instruments TMS320C6454 User Manual
Page 27
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PRODUCT PREVIEW
TMS320C6454
Fixed-Point Digital Signal Processor
SPRS311A – APRIL 2006 – REVISED DECEMBER 2006
Table 2-3. Terminal Functions (continued)
SIGNAL
TYPE
(1)
IPD/IPU
(2)
DESCRIPTION
NAME
NO.
ACE5
V27
O/Z
IPU
EMIFA memory space enables
ACE4
V28
O/Z
IPU
•
Enabled by bits 28 through 31 of the word address
ACE3
W26
O/Z
IPU
•
Only one pin is asserted during any external data access
Note: The C6454 device does not have ACE0 and ACE1 pins
ACE2
W27
O/Z
IPU
ABE7
W29
O/Z
IPU
ABE6
K26
O/Z
IPU
ABE5
L29
O/Z
IPU
EMIFA byte-enable control
ABE4
L28
O/Z
IPU
•
Decoded from the low-order address bits. The number of address bits or
byte enables used depends on the width of external memory.
ABE3
AA29
O/Z
IPU
•
Byte-write enables for most types of memory.
ABE2
AA28
O/Z
IPU
ABE1
AA25
O/Z
IPU
ABE0
AA26
O/Z
IPU
EMIFA (64-BIT) - BUS ARBITRATION
AHOLDA
N26
O
IPU
EMIFA hold-request-acknowledge to the host
AHOLD
R29
I
IPU
EMIFA hold request from the host
ABUSREQ
L27
O
IPU
EMIFA bus request output
EMIFA (64-BIT) - ASYNCHRONOUS/SYNCHRONOUS MEMORY CONTROL
EMIFA external input clock. The EMIFA input clock (AECLKIN or SYSCLK4
AECLKIN
N29
I
IPD
clock) is selected at reset via the pullup/pulldown resistor on the AEA[15] pin.
Note: AECLKIN is the default for the EMIFA input clock.
AECLKOUT
V29
O/Z
IPD
EMIFA output clock [at EMIFA input clock (AECLKIN or SYSCLK4) frequency]
Asynchronous memory write-enable/Programmable synchronous interface
AAWE/ASWE
AB25
O/Z
IPU
write-enable
AARDY
K29
I
IPU
Asynchronous memory ready input
AR/W
W25
O/Z
IPU
Asynchronous memory read/write
AAOE/ASOE
Y28
O/Z
IPU
Asynchronous/Programmable synchronous memory output-enable
Programmable synchronous address strobe or read-enable
•
For programmable synchronous interface, the r_enable field in the Chip
Select x Configuration Register selects between ASADS and ASRE:
ASADS/ASRE
R26
O/Z
IPU
–
If r_enable = 0, then the ASADS/ASRE signal functions as the ASADS
signal.
–
If r_enable = 1, then the ASADS/ASRE signal functions as the ASRE
signal.
Device Overview
27