15-6
MC9328MX1 Reference Manual
MOTOROLA
Analog Signal Processor (ASP)
•
IDLECNT (t3)—Idle count: This controls the idle time after each set of measurement. During the
idle time, all touch panel control switches are turned off, hence saving current consumption by the
touch panel.
NOTE:
For channels X and Y, DSCNT must be at least 1 to allow sufficient settling
time of the touch panel and the MUX.
The best value for the analog clock ACLK is 12 MHz, which can be controlled by the PADC_CLK field of
the Clock Divide Register. The decimation ratio of the filter is 1260, therefore fclk = ACLK/1260. When
ACLK = 12 MHz, fclk will be 9.6 kHz.
Some examples are provided to illustrate how to calculate the output data rate:
1. If MOD [1:0] = 01 and AZE = 0, the X and Y channels are selected and the auto-zero
measurement is disabled. The maximum output data rate for each channel is 2.4 kHz when
DSCNT = 1, DMCNT = 0 and IDLECNT = 0.
To get a 200Hz output data rate, set DSCNT = 1, DMCNT = 0, and IDLECNT = 44
2. If MOD [1:0] = 10 and AZE = 1, all the channels are selected, with auto-zero measurement
enabled. Maximum output data rate for each channel is 1.2 kHz when DSCNT = 1,
DMCNT = 0 and IDLECNT = 0.
To get a 200Hz output data rate, set DSCNT = 1, DMCNT = 7 (for example, if the
decimation ratio = 8, and IDLECNT = 12.
3. If MOD [1:0] = 11, only U channel is selected and the AZE bit is ignored. Maximum output
data rate is 9.6 kHz when DMCNT = 0 and IDLECNT = 0. DSCNT can be set to 0 as there
is no need for the settling time for the touch panel and MUX.
To get a 200Hz output data rate, set DSCNT = 0, DMCNT = 0, and IDLECNT = 47.
Table 15-5. Output Data Rate Equations
MOD
AZE
Equations for Output Data Rate
01
0
(X,Y,X,Y, ...)
01
1
(Z,X,Y,Z,X,Y, ....)
10
0
(X,Y,U,X,Y,U, ...)
10
1
(Z,X,Y,U,Z,X,Y,U, ...)
11
X
(U,U,U, ...)
fclk
2
DSCNT DMCNT 1
+
+
(
)
×
IDLECNT
+
------------------------------------------------------------------------------------------------------------
DSCNT 1
)
≥
(
fclk
3
DSCNT DMCNT 1
+
+
(
)
×
IDLECNT
+
------------------------------------------------------------------------------------------------------------
DSCNT 1
)
≥
(
fclk
3
DSCNT DMCNT 1
+
+
(
)
×
IDLECNT
+
------------------------------------------------------------------------------------------------------------
DSCNT 1
)
≥
(
fclk
4
DSCNT DMCNT 1
+
+
(
)
×
IDLECNT
+
------------------------------------------------------------------------------------------------------------
DSCNT 1
)
≥
(
fclk
DSCNT DMCNT 1
+
+
(
)
IDLECNT
+
---------------------------------------------------------------------------------------------------
DSCNT 0
)
≥
(
Summary of Contents for DragonBall MC9328MX1
Page 68: ...1 12 MC9328MX1 Reference Manual MOTOROLA Introduction ...
Page 86: ...2 18 MC9328MX1 Reference Manual MOTOROLA Signal Descriptions and Pin Assignments ...
Page 116: ...3 30 MC9328MX1 Reference Manual MOTOROLA Memory Map ...
Page 126: ...4 10 MC9328MX1 Reference Manual MOTOROLA ARM920T Processor ...
Page 160: ...8 8 MC9328MX1 Reference Manual MOTOROLA System Control ...
Page 272: ...13 32 MC9328MX1 Reference Manual MOTOROLA DMA Controller ...
Page 281: ...Programming Model MOTOROLA Watchdog Timer Module 14 9 ...
Page 282: ...14 10 MC9328MX1 Reference Manual MOTOROLA Watchdog Timer Module ...
Page 300: ...15 18 MC9328MX1 Reference Manual MOTOROLA Analog Signal Processor ASP ...
Page 438: ...18 16 MC9328MX1 Reference Manual MOTOROLA Serial Peripheral Interface Modules SPI 1 and SPI 2 ...
Page 478: ...19 40 MC9328MX1 Reference Manual MOTOROLA LCD Controller ...
Page 574: ...21 32 MC9328MX1 Reference Manual MOTOROLA Memory Stick Host Controller MSHC Module ...
Page 598: ...23 16 MC9328MX1 Reference Manual MOTOROLA Real Time Clock RTC ...
Page 670: ...24 72 MC9328MX1 Reference Manual MOTOROLA SDRAM Memory Controller ...
Page 726: ...25 56 MC9328MX1 Reference Manual MOTOROLA SmartCard Interface Module SIM ...
Page 736: ...26 10 MC9328MX1 Reference Manual MOTOROLA General Purpose Timers ...
Page 854: ...29 18 MC9328MX1 Reference Manual MOTOROLA I2C Module ...
Page 900: ...30 46 MC9328MX1 Reference Manual MOTOROLA Synchronous Serial Interface SSI ...
Page 942: ...32 26 MC9328MX1 Reference Manual MOTOROLA GPIO Module and I O Multiplexer IOMUX ...