Motorola DSP56012 ユーザーズマニュアル

T states). When the DSP is driven by a stable external clock source, setting the SD bit 
before executing the STOP instruction will allow a faster start up of the DSP.

The DSP56012 operating modes are defined as described below and summarized in 

during reset and can be changed by writing to the OMR.

The operating modes are described in the following paragraphs.

Mode 0

In this mode, the internal Program RAM is enabled and the bootstrap 
ROM is disabled. All bootstrap programs end by selecting this 
operating mode. This mode is identical to DSP56002 Mode 0. 

It is not possible to reach operating Mode 0 during hardware reset. Any 
attempt to start up in Mode 0 defaults to Mode 1. 

Mode 1

In this mode, the bootstrap ROM is enabled and the bootstrap 
program is executed after hardware reset. The internal Program RAM 
is loaded with up to 256 words from the parallel Host Interface.

Mode 2

Reserved.

Mode 3

Reserved. 

It is not possible to reach operating Mode 3 during hardware reset. Any 
attempt to start up in Mode 3 defaults to Mode 1.

Mode 4

In this mode, the bootstrap ROM is enabled and the bootstrap 
program is executed after hardware reset. The bootstrap program 

Operating Modes  

0

000

Normal operation, bootstrap disabled

1

001

Bootstrap from parallel Host Interface

2

010

Reserved

3

011

Reserved

4

100

Wake up in Program ROM address $0A00 

5

101

Bootstrap from SHI (SPI mode)

6

110

Reserved

7

111

Bootstrap from SHI (I

2

C mode)