Memory interface control registers, Primary-bus control register, 1 primary-bus control register – Texas Instruments TMS320C3x User Manual

Page 273: Figure 9–2. primary-bus control register

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Memory Interface Control Registers

9-7

TMS320C30 and TMS320C31 External-Memory Interface

9.3

Memory Interface Control Registers

Two memory interface control registers, the primary-bus control register and
the expansion-bus control register, are described in this section.

9.3.1

Primary-Bus Control Register

The primary bus control register is a 32-bit register that contains the control bits
for the primary bus (see Figure 9–2). Table 9–3 describes the register bits with
the bit names and functions.

Figure 9–2. Primary-Bus Control Register

2

1

0

SWW

WTCNT

BNKCMP

xx

xx

3

4

5

6

7

8

9

10

11

12

15–13

31–16

HOLDST

NOHOLD

HIZ

R/W

R/W

R/W

R

R/W

R/W

Notes:

1) xx = reserved bit, read as 0

2) R = read, W = write

Note:

After changing the bit fields of the primary-bus control register, up to three
instructions are fetched before the primary bus is reconfigured because the
configuration change is performed in the execute stage of the pipeline.

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