Texas Instruments TMS320C2XX User Manual

Page 426

Advertising
background image

’C209 Memory and I/O Spaces

11-8

(4K) are mapped to external data memory. Thus, a total of 8K additional
addresses (4K program and 4K data) are available for external memory.

DARAM blocks B1 and B2 are fixed, but DARAM block B0 may be mapped to
program space or data space, depending on the value of the CNF bit (bit 12
of status register ST1):

-

When CNF = 0, B0 is mapped to data space and is accessible at data ad-
dresses 0200h–02FFh. Note that the addressable external

program

memory increases by 512 words. At reset, CNF = 0.

-

When CNF = 1, B0 is mapped to program space and is accessible at pro-
gram addresses FF00h–FFFFh.

Table 11–1 lists the available program memory configurations for the ’C209;
Table 11–2 lists the data-memory configurations. Note these facts:

-

Program-memory addresses 0000h–003Fh are used for the interrupt vec-
tors.

-

Data-memory addresses 0000h–005Fh contain on-chip memory-mapped
registers and reserved memory.

-

Two other on-chip data-memory ranges are always reserved:
0080h–01FFh and 0400h–07FFh.

Table 11–1.

’C209 Program-Memory Configuration Options

MP/MC

RAMEN

CNF

ROM
(hex)

SARAM

(hex)

DARAM B0

(hex)

External

(hex)

Reserved

(hex)

0

0

0

0000–0FFF

1000–FFFF

0

0

1

0000–0FFF

FF00–FFFF

1000–FDFF

FE00–FEFF

0

1

0

0000–0FFF

1000–1FFF

2000–FFFF

0

1

1

0000–0FFF

1000–1FFF

FF00–FFFF

2000–FDFF

FE00–FEFF

1

0

0

0000–FFFF

1

0

1

FF00–FFFF

0000–FDFF

FE00–FEFF

1

1

0

1000–1FFF

0000–0FFF

2000–FFFF

1

1

1

1000–1FFF

FF00–FFFF

0000–0FFF

2000–FDFF

FE00–FEFF

Advertising