Motorola DragonBall MC9328MX1 Reference Manual page 292

Analog Signal Processor (ASP)
Name
AZ_SEL Auto-Zero Position Selection—Selects the position of
Bit 20 auto-zero measurement.
Reserved Reserved—These bits are reserved and should read 0.
Bits 19–16
AZE Auto-Zero Enable—Enables/Disables the auto-zero
Bit 15 measurement.
AUTO Auto Sampling—Enables/Disables Pen A/D auto sampling
Bit 14 function. When set, transistor switches are sampled for
selected analog inputs X, Y, or U. This process repeats
when the IDLE counter reaches zero. In AUTO mode, the
IDLE counter is reloaded when it reaches zero.
MOD Mode—Selects the analog input signals for A/D sampling
Bits 13–12 dependent on AUTO bit setting. See Table 15-3.
SW8 Switch Control—Turns the transistor switches on/off when
Bit 11 the AUTO function is off or when the Pen A/D is off in touch
panel idle state.
SW7
Bit 10
In manual modes, switches are set according to the
configuration of SW[8...1] bits.
SW6
Bit 9
In auto modes, switches are set by internal logic. SW[8...1]
are ignored and should be set to 0. Normal settings for
SW5
sampling X is [11000110]; Y is [00111001].
Bit 8
Exception cases occur when ACAL bit or ASWB bits are
SW4
set.
Bit 7
SW3
Bit 6
SW2
Bit 5
SW1
Bit 4
Reserved Reserved—These bits are reserved and should read 0.
Bits 3–2
15-10
Table 15-7. Control Register Description (Continued)
Description
MC9328MX1 Reference Manual
Settings
0 = Measurement taken without the
external resistor at the R1a
and R2a pins
1 = Measurement taken with the
external resistor at R1a and
R2a pins
0 = No auto-zero measurement
1 = Auto-zero measurement taken
before every pin input
measurement
0 = Auto sampling off (Manual
mode sampling is selected)
1 = Auto sampling on
00 = No input signal selected
01 = Auto XY, or Manual X
10 = Auto XYU, or Manual Y
11 = selects only U
0 = Transistor off
1 = Transistor on
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