Intel Celeron 365 HH80552RE104512 User Manual

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In most cases, termination resistors are not required as these are integrated into the 

processor silicon. See 

 for details on which GTL+ signals do not include on-die 

termination. 

Valid high and low levels are determined by the input buffers by comparing with a 

reference voltage called GTLREF. 

 lists the GTLREF specifications. The GTL+ 

Reference voltage (GTLREF) should be generated on the system board using high 

precision voltage divider circuits. 

1. Unless otherwise noted, all specifications in this table apply to all processor frequencies.

GTLREF_PU

GTLREF pull up resistor

124 * 0.99

124

124 * 1.01

Ω

2,3

2. GTLREF is to be generated from V

TT

 by a voltage divider of 1% resistors (one divider for each GTLREF

land). 

3. For Intel 865 Express chipset LGA775 boards only, the GTLREF_PU should be 49.9 Ω 1%, and the GTLREF_PD should

be 100 Ω 1%.

GTLREF_PD

GTLREF pull down resistor

210 * 0.99

210

210 * 1.01

Ω

R

PULLUP

On die pull-up for BOOTSELECT 
signal

500

—

5000

Ω

4

4. These pull-ups are to V

TT

.

R

TT

60 Ω Platform Termination 
Resistance

51

60

66

Ω

5

5. R

TT

 is the on-die termination resistance measured at V

TT

/2 of the GTL+ output driver. The IMPSEL land

is used to select a 50 Ω or 60 Ω buffer and R

TT

 value. 

50 Ω Platform Termination 
Resistance

39

50

55

Ω

COMP[1:0]

60 Ω Platform Termination
COMP Resistance

59.8

60.4

61

Ω

6

6.

COMP resistance must be provided on the system board with 1% resistors. COMP[1:0] resistors are

to V

SS

. COMP[5:4] resistors are to V

TT

.

50 Ω Platform Termination
COMP Resistance

49.9 * 0.99

49.9

49.9 * 1.01

Ω

COMP[5:4]

60 Ω Platform Termination
COMP Resistance

59.8

60.4

61

Ω

50 Ω Platform Termination
COMP Resistance

49.9 * 0.99

49.9

49.9 * 1.01

Ω