 Boot Loader
The 'C32's boot loader is an
enhanced version of that found in the 'C31. The boot
loader functions as a memory boot loader, memory boot
loader with handshake, or a serial port boot loader. The
boot loader mode selection is determined by the status of
the external interrupt pins (/INT0-/INT3) immediately
following reset as shown in the following table:
| /INT0 |
/INT1 |
/INT2 |
/INT3 |
Boot Loader Mode |
Source Program Location |
0
|
1
|
1
|
1
|
External
Memory
|
Boot 1
address 1000h
|
1
|
0
|
1
|
1
|
External
Memory
|
Boot 2
address 810000h
|
1
|
1
|
0
|
1
|
External
Memory
|
Boot 3
address 900000h
|
1
|
1
|
1
|
0
|
32-bit fixed
burst serial
|
Serial Port
|
0
|
1
|
1
|
0
|
External
Memory with Handshake
|
Boot 1
address 1000h, XF0 and XF1 used in handshaking
|
1
|
0
|
1
|
0
|
External
Memory with Handshake
|
Boot 2
address 810000h, XF0 and XF1 used in handshaking
|
1
|
1
|
0
|
0
|
External
Memory with Handshake
|
Boot 3
address 900000h, XF0 and XF1 used in handshaking
|
The memory boot loader supports:
- User-definable byte, half-word, and full-word
data formats, allowing the flexibility to load a
source program from memories having widths of 8,
16, and 32 bits with or without handshaking.
- The source programs to be loaded reside in one of
three memory locations: 1000h (STRB0), 810000h
(IOSTRB), and 900000h (STRB1).
- The serial port boot loader supports 32 bit fixed
burst loads from the 'C32's serial port with an
externally generated serial port clock and FSR.
- The handshaking mode utilizes XF0 and XF1 as data
acknowledge and data ready signals, respectively.
- The TMS320C32's boot loader waits until
the host sets XF1 low to read in the
data. While the TMS320C32 waits for XF1
to drop low, the pin pulses. Setting XF1
low communicates to the TMS320C32 that
the data is valid. The IACK pulses
indicate that the TMS320C32 is waiting
for data.
- The boot loader sets XF0 low after
reading the data value. Dropping XF0
acknowledges to the host that the data
was read.
- The host sets XF1 high to inform the
TMS320C32 that the data is no longer
valid.
- Finally, the TMS320C32 terminates the
transfer by setting XF0 high.
Handshake Data Transfer
Operation
|
