7.MISCELLANEOUS FUNCTIONS

7.1Processor Identification

Four read-only registers are provided to allow software to identify the Rabbit micropro- cessor and recognize the features and capabilities of the chip. Five bits in each of these registers are unique to each version of the chip. One register is reserved for the on-chip flash memory configuration (GROM), one register is reserved for the on-chip RAM mem- ory configuration (GRAM), one register identifies the CPU (GCPU), and the final register is reserved for revision identification (GREV). The Rabbit 3000 does not contain on-chip SRAM or flash memories.

Table 7-1. Global ROM Configuration Register

Global ROM Configuration Register

(GROM)

(Address = 0x2C)

 

 

 

 

 

Bit(s)

Value

 

Description

 

 

 

 

 

7

0

Program fetch as a function of the SMODE pins.

 

 

 

 

 

(read only)

1

Ignore the SMODE pins program fetch function.

 

 

 

 

 

6:5

read

These bits report the state of the SMODE pins.

 

 

 

 

 

4:0

00000

ROM identifier for this version of the chip.

 

 

 

 

 

 

Table 7-2. Global RAM Configuration Register

Global RAM Configuration Register

(GRAM)

(Address = 0x2D)

 

 

 

 

 

Bit(s)

Value

 

Description

 

 

 

 

 

7

0

Program fetch as a function of the SMODE pins.

 

 

 

 

 

(read only)

1

Ignore the SMODE pins program fetch function.

 

 

 

 

 

6:5

read

These bits report the state of the SMODE pins.

 

 

 

 

 

4:0

00000

RAM identifier for this version of the chip.

 

 

 

 

 

 

User’s Manual

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Jameco Electronics 3000, 2000 manual Miscellaneous Functions, Processor Identification, Global ROM Configuration Register