Texas Instruments TMS320C6454 用户手册
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PRODUCT PREVIEW
3.6 JTAG ID (JTAGID) Register Description
3.7 Pullup/Pulldown Resistors
TMS320C6454
Fixed-Point Digital Signal Processor
SPRS311A – APRIL 2006 – REVISED DECEMBER 2006
Table 3-13. Device Status Register (DEVSTAT) Field Descriptions (continued)
Bit
Field
Value
Description
3:0
BOOTMODE[3:0]
Boot mode configuration bits
Shows the status of what device boot mode configuration is operational.
BOOTMODE[3:0]
[Note: if selected for boot, the corresponding peripheral is automatically enabled after device reset.]
Shows the status of what device boot mode configuration is operational.
BOOTMODE[3:0]
[Note: if selected for boot, the corresponding peripheral is automatically enabled after device reset.]
0000
No boot (default mode)
0001
Host boot (HPI)
0010
Reserved
0011
Reserved
0100
EMIFA 8-bit ROM boot
0101
Master I2C boot
0110
Slave I2C boot
0111
Host boot (PCI)
1000
Reserved
thru
1111
For more detailed information on the boot modes, see
, Boot Sequence.
The JTAG ID register is a read-only register that identifies to the customer the JTAG/Device ID. For the
C6454 device, the JTAG ID register resides at address location 0x02A8 0008. For the actual register bit
names and their associated bit field descriptions, see
C6454 device, the JTAG ID register resides at address location 0x02A8 0008. For the actual register bit
names and their associated bit field descriptions, see
and
.
31
28 27
12 11
1
0
VARIANT
PART NUMBER
MANUFACTURER
LSB
(4-bit)
(16-bit)
(11-bit)
R-n
R-0000 0000 1000 1010b
0000 0010 111b
R-1
LEGEND: R = Read only; -n = value after reset
Figure 3-11. JTAG ID (JTAGID) Register - 0x02A8 0008
Table 3-14. JTAG ID (JTAGID) Register Field Descriptions
Bit
Field
Value
Description
31:28
VARIANT
Variant (4-Bit) value. The value of this field depends on the silicon revision being
used. For more information, see the TMS320C6455/54 Digital Signal Processor
Silicon Errata (literature number
used. For more information, see the TMS320C6455/54 Digital Signal Processor
Silicon Errata (literature number
Note: the VARIANT field may be invalid if no CLKIN1 signal is applied.
27:12
PART NUMBER
Part Number (16-Bit) value. C6454 value: 0000 0000 1000 1010b.
11:1
MANUFACTURER
Manufacturer (11-Bit) value. C6454 value: 0000 0010 111b.
0
LSB
LSB. This bit is read as a "1" for C6454.
Proper board design should ensure that input pins to the C6454 device always be at a valid logic level and
not floating. This may be achieved via pullup/pulldown resistors. The C6454 device features internal pullup
(IPU) and internal pulldown (IPD) resistors on most pins to eliminate the need, unless otherwise noted, for
external pullup/pulldown resistors.
not floating. This may be achieved via pullup/pulldown resistors. The C6454 device features internal pullup
(IPU) and internal pulldown (IPD) resistors on most pins to eliminate the need, unless otherwise noted, for
external pullup/pulldown resistors.
An external pullup/pulldown resistor needs to be used in the following situations:
•
Device Configuration Pins: If the pin is both routed out and 3-stated (not driven), an external
pullup/pulldown resistor must be used, even if the IPU/IPD matches the desired value/state.
pullup/pulldown resistor must be used, even if the IPU/IPD matches the desired value/state.
Device Configuration
67