Datasheet

AD7877 Data Sheet
Rev. D | Page 34 of 44
Table 15. Read Register Map
Register Address
Binary
RADD4 RADD3 RADD2 RADD1 RADD0 Hex Register Name Description
0
0
0
0
0
00
None
Reads back all zeros
0 0 0 0 1 01 Control Register 1 See Table 13
0 0 0 1 0 02 Control Register 2 See Table 13
0 0 0 1 1 03
Alert status/enable
register
See Table 13
0 0 1 0 0 04 AUX1 high limit See Table 13
0 0 1 0 1 05 AUX1 low limit See Table 13
0 0 1 1 0 06 BAT1 high limit See Table 13
0
0
1
1
1
07
BAT1 low limit
See Table 13
0 1 0 0 0 08 BAT2 high limit See Table 13
0 1 0 0 1 09 BAT2 low limit See Table 13
0
1
0
1
0
0A
TEMP1 low limit
See Table 13
0 1 0 1 1 0B TEMP1 high limit See Table 13
0 1 1 0 0 0C Sequencer Register 0 See Table 13
0
1
1
0
1
0D
Sequencer Register 1
See Table 13
0 1 1 1 0 0E DAC register See Table 13
0 1 1 1 1 0F None Factory use only
1
0
0
0
0
10
X+
Measurement at X+ input for Y position
1 0 0 0 1 11 Y+ Measurement at Y+ input for X position
1 0 0 1 0 12 Y− (Z2)
Measurement at Y− input for touch-pressure
calculation Z2
1 0 0 1 1 13 AUX1 Auxiliary Input 1 measurement
1 0 1 0 0 14 AUX2 Auxiliary Input 2 measurement
1 0 1 0 1 15 AUX3 Auxiliary Input 3 measurement
1 0 1 1 0 16 BAT1 Battery Input 1 measurement
1
0
1
1
1
17
BAT2
Battery Input 2 measurement
1 1 0 0 0 18 TEMP1 Single-ended temperature measurement
1 1 0 0 1 19 TEMP2 Differential temperature measurement
1
1
0
1
0
1A
X+ (Z1)
Measurement at X+ input for touch-pressure
calculation Z1
1 1 0 1 1 1B
GPIO Control
Register 1
See Table 14
1 1 1 0 0 1C
GPIO Control
Register 2
See Table 14
1 1 1 0 1 1D GPIO data See Table 14
1 1 1 1 0 1E None Factory use only
1
1
1
1
1
1F
None
Factory use only