Intel 80C188XL Refresh Clock Interval Register, Rftime, Sets refresh rate, Register Name

Models: 80C186XL 80C188XL

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Refresh Clock Interval Register

REFRESH CONTROL UNIT

Register Name:

Refresh Clock Interval Register

Register Mnemonic:

RFTIME

Register Function:

Sets refresh rate.

15

R C 8

R

R

R

R

C

C

C

C

7

6

5

4

 

 

 

 

0

R

R

R

R

C

C

C

C

3

2

1

0

 

 

 

 

 

 

 

A1288-0A

 

 

 

 

Bit

Bit Name

Reset

Function

Mnemonic

State

 

 

 

 

 

 

RC8:0

Refresh Counter

000H

Sets the desired clock count between refresh

 

Reload Value

 

cycles.

 

 

 

 

NOTE: Reserved register bits are shown with gray shading. Reserved bits must be written to a logic zero to ensure compatibility with future Intel products.

Figure 7-7. Refresh Clock Interval Register

7.7.2.3Refresh Control Register

Figure 7-8 shows the Refresh Control Register. The user may read or write the REN bit at any time to turn the Refresh Control Unit on or off. The lower nine bits contain the current nine-bit down-counter value. The user cannot program these bits. Disabling the Refresh Control Unit clears both the counter and the corresponding counter bits in the control register.

7-9

Page 188
Image 188
Intel 80C188XL, 80C186XL Refresh Clock Interval Register, Rftime, Sets refresh rate, Register Name, Register Mnemonic