BU21028FV-M Datasheet, PDF (23/36 Pages) Rohm – 4-wire Resistive Touch Screen Controller

BU21028FV-M
Register Description
Table 12. CFR0 Register (PAGE=0, ADDR=0x0, Reset value=0x20)
D7
D6
D5
D4
D3
D2
RSV0 RSV0 CALIB INTRM RSV0 RSV0
Bits D7-D6, D3-D0: RSV0
Reserved. Set these bits to 0.
D1
RSV0
D0
RSV0
Bit D5 : CALIB
Internal parameter setting-1 for calibration of dual touch detection
0= Not to use calibration result
1= Use calibration result
Bit D4 : INTRM
Setting of INT state in case BU21028FV-M is active after conversion by “PDM” setting
0= depend on “pen-down”
1= always output “0”
Table 13. CFR1 Register (PAGE=0, ADDR=0x1, Reset value=0xA6)
D7
D6
D5
D4
D3
D2
D1
D0
MAV
AVE[2:0]
-
SMPL[2:0]
Bit D7: MAV
Median Average Filter
0= Off
1= On
Bits D6-D4: AVE
AVE+1= The number of average samples setting for MAV. If AVE is greater than SMPL, AVE takes the value of
SMPL.
Bits D2-D0: SMPL
SMPL+1= The number of conversion samples setting for MAV.
Ex. In the case of CFR1 = 0xA6 (the number of average samples is 3 and the number of conversion samples is 7)
Conversion result
{ 1676, 1688, 1656, 1677, 1659, 1702, 4095 }
Sorted result
{ 1656, 1659, 1676, 1677, 1688, 1702, 4095 }
Chose 3 center data
{ 1656, 2.79, 1676, 1677, 1688, 1702, 4095 }
Average above 3 data = (1676 + 1677 + 1688) / 3 =1680 (vs averaged all six data = 2022)
www.rohm.com
© 2016 ROHM Co., Ltd. All rights reserved.
TSZ22111 • 15 • 001
23/32
TSZ02201-0L5L0F300720-1-2
27.May.2016 Rev.002