TMS320C32 Boot Loader
11-23
Using the TMS320C31 and TMS320C32 Boot Loaders

11.2.5 Boot-Loader Hardware Interface

The hardware interface for the memory boot load uses the STRBX_B3 through

STRBX_B0 pins as strobe byte-enable pins (see Figure 11–8). The hardware

interface is independent of the boot source memory width. This interface

is identical to the 32-bit-wide memory interface described in Case 2, in Section

10.6 on page 10-20. For 16-bit memory widths, remove the two left-most

memory devices of Figure 11–8. For 8-bit memory widths, remove all but the

right-most of the memory devices of Figure 11–8.

Figure 11–8. External Memory Interface for Source Data Stream Memory Boot Load
’C32
STRBX_B3
STRBX_B2
STRBX_B1
STRBX_B0
D(31–24)
D(23–16)
D(15–8)
D(7–0)
I/O(7-0)
A23
A22
A21
A20
A2
A1
A0
. . .
. . .
A23
A22
A21
A20
A2
A1
A0
. . .
CS I/O(7-0)
. . .
A23
A22
A21
A20
A2
A1
A0
. . .
CS I/O(7-0)
. . .
A23
A22
A21
A20
A2
A1
A0
. . .
CS I/O(7-0)
. . .
A23
A22
A21
A20
A2
A1
A0
. . .
CS
16–bit wide EPROM
32–bit wide EPROM
8–bit wide EPROM

11.2.6 TMS320C32 Boot-Loader Precautions

The interrupt flags are not reset by the boot-loader function. If pending interrupts

are to be avoided when interrupts are enabled, clear the IF register before enabling

interrupts.

The MCBL/MP pin should remain high during the entire boot-loading execution,

but it can be changed subsequently at any time. The ’C32 does not need to be

reset after the MCBL/MP pin is changed. During the change, the ’C32 should

not access addresses Oh–FFh. The memory space Oh–FFFh is mapped to

external memory three clock cycles after changing the MCBL/MP pin.