WM9713L_06 WOLFSON [Wolfson Microelectronics plc], WM9713L_06 Datasheet - Page 66

• Manufacturer Part Number: WM9713L_06
• Description: AC 97 Audio + Touchpanel CODEC
• Manufacturer: WOLFSON [Wolfson Microelectronics plc]

WM9713L
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Table 50 Touchpanel Digitiser Data
When operating in co-ordinate mode (COO=1) there will be 3 results to read back from each set of
measurements – namely X,Y and the third additional measurement. After the co-ordinate set has
finished the X result will be present in register 7Ah. Once this has been read back by the user the Y
result will overwrite register 7Ah, as indicated by ADCSRC. Finally, after the Y result has been read
back, the result of the third, additional, measurement will become present in 7Ah, again indicated by
ADCSRC.
To avoid losing data that has not yet been read, the WM9713L can delay overwriting register 7Ah
with new conversions until the old data has been read. This function is enabled using the WAIT bit,
and applies to both single and co-ordinate conversion mode.
The flow diagram in Figure 24 shows the timing of touchpanel conversions, and data readback from
register 7Ah - dependent on the individual settings of the CO, POLL,ADCSEL and CTC bits.
7Ah
or
AC-Link slot
selected by
SLT
78h
REGISTER
ADDRESS
15
14:12
11:0
9
BIT
PNDN
ADCSRC
ADCD
WAIT
LABEL
0
000
000h
0
DEFAULT
Pen status (read-only)
0: Pen Up
1: Pen Down
Touchpanel ADC Source
000: No measurement
001: X co-ordinate measurement
010: Y co-ordinate measurement
011: Pressure measurement (4-wire only)
100: COMP1/AUX1 measurement (pin 29)
101: COMP2/AUX2 measurement (pin 30)
110: AUX3 measurement (SPKVDD pin)
111: WIPER/AUX4 measurement (pin 12)
Touchpanel ADC Data (read-only)
Bit 11 = MSB
Bit 0 = LSB
0: No effect (new ADC data overwrites
unread data in register 7Ah)
1: New data is held back, and
measurements delayed, until register 7Ah is
read)
DESCRIPTION
PP Rev 3.0 June 2006
Pre-Production
66