REGISTERS

CCR1

CCR1

no direct access

The chip configuration 1 (CCR1) register enables the watchdog timer and selects the bus timing mode. Two of its bits combine with three bits of CCR0 to control wait states and bus width.

7

1

1

0

1

 

 

 

 

0

WDE

BW1

IRC2

0

 

 

 

 

Bit

Bit

 

 

Function

Number

Mnemonic

 

 

 

 

 

 

 

 

7:6

1

To guarantee proper operation, write ones to these bits.

 

 

 

5

0

To guarantee proper operation, write zero to this bit.

 

 

 

4

1

To guarantee proper operation, write one to this bit.

 

 

 

3

WDE

Watchdog Timer Enable

 

 

Selects whether the watchdog timer is always enabled or enabled the

 

 

first time it is cleared.

 

 

0

= always enabled

 

 

1

= enabled first time it is cleared

 

 

 

2

BW1

Buswidth Control

 

 

This bit, along with the BW0 bit (CCR0.1), selects the bus width.

 

 

BW1 BW0

 

 

 

0

0

illegal

 

 

0

1

16-bit only

 

 

1

0

8-bit only

 

 

1

1

BUSWIDTH pin controlled

 

 

 

 

 

The CCRs are loaded with the contents of the chip configuration bytes (CCBs) after reset, unless the microcontroller is entering programming modes (see “Entering Programming Modes” on page 16-13), in which case the programming chip configuration bytes (PCCBs) are used. The CCBs reside in nonvolatile memory at addresses 2018H (CCB0) and 201AH (CCB1).

C-13

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Image 490
Intel 8XC196MH, 8XC196MD, 8XC196MC manual CCR1