STMPE812 datasheet(24/51 Pages) STMICROELECTRONICS

24 / 51 page

ADC controller

STMPE812

24/51

Doc ID 17732 Rev 3

ADC control register

ADC control

Address:

0x20

Type:

R/W

Reset:

0x32

Description:

This register is used to configure the ADC operations.

7654

ADC_MODE

ADC_CAP

ADC_FREQ

CP_ARM

CP_Lock[1:0]

ADC_PORT

0011

[7] ADC_MODE: ADC capture mode

‘0’ – Continuous capture according to sampling rate specified by ADC_FREQ register. New

data over-writes old data in ADC_DATA register.

‘1’ – One-shot capture. One sample is taken every time system writes ‘1’ to ADC_CAP bit

[6] ADC_CAP: ADC channel data capture

In one-shot mode:

Write ‘1’ to initiate data acquisition for the corresponding channel. Writing ‘0’ has no effect.

Reads ‘1’ if conversion is in progress.Reads ‘0’ if conversion is completed.

One-shot mode ADC generates interrupt in corresponding interrupt status bit on completion of

conversion

In continuous capture mode:

Write ‘1’ to initiate data acquisition for the corresponding channel. Writing ‘0’ to stop capturing.

[5:4] ADC_FREQ: ADC sampling frequency based on 1MHz RC (minimum 880 KHz)

00 – 10 K samples/sec

01 – 12.5 K samples/sec

10 – 15 K samples/sec

11 – 20 K samples/sec

NOTE: As the ADC is also used for TSC operation. This setting affects the maximum sampling

rate possible with TSC.

[3] CP_Arm: Writing ‘1’ arms the charge-pump for unlocking

Writing ‘0’ un-arms it

Charge-pump is required for ADC/TSC operation when Vcc is less than 2.5V. Activating the

charge pump when Vcc is more than 2.5V may result in permanent damage of the

device.

Charge-pump can be activated by unlocking CP_Lock after it is armed.

[2:1] CP_Lock[1:0]: Only effective if CP_Arm is set to ‘1’.

Always reads ‘00’.

Writing ‘01’ when CP_Arm is ‘1’ activates the charge pump.

Writing ‘00’, ‘10’ and ‘11’ does NOT activate the charge-pump, and clears the CP_Arm bit.

CP_Arm MUST BE set before writing to CP_Lock. Accesses to CP_Lock is ignored, if CP_Arm

is ‘0’.

Note: NOTE: CP_Arm and CP_Lock CANNOT be accessed in a single I2C transaction.

System must first ARM the CP with 1 I2C transaction, and unlocks it in the next.

CP_LOCK reads “00” if charge pump is activated

CP_LOCK reads “01” if charge pump is not activated

Obsolete

Product(s)

- Obsolete

Product(s)

STMPE812 数据表(PDF) 24 Page - STMicroelectronics

STMPE812 数据表(HTML) 24 Page - STMicroelectronics

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

数据表下载