MPR084

Sensors

Freescale Semiconductor

15

Preliminary

4.3

Run1 Mode

When in Run1 mode the sensor controller will run continuously. During Run1 all the modules are synchronized by the Master Tick

Period. This value can be set by using the Master Tick Period Register as outlined in the following section.

This mode is enabled by setting the Configuration Register’s RUNE and DCE bits high.

4.3.1

Master Tick Period Register

The Master Tick Period Register is used to set the master tick of this system. All parts of the system are synchronized to this

counter. This register is overridden in all modes except for Run1. When not in Run1 mode, the value of this register is ignored

Figure 18. Master Tick Period Register

4.4

Run2 Mode

When in Run2 mode the sensor controller will continue to scan the electrodes but a low power state will be enabled between

If DCE is enabled the sensor controller transitions between low power and active states. During the active part of the cycle

communication with the sensor controller is possible; however, Freescale always requires users to issue an ATTN signal prior to

to produce invalid data.

This mode is enabled by setting the Configuration Register’s RUNE bit high and DCE bit low. The only way to exit this mode is

to toggle the Attention Pin, refer to Section 4.7.

4.5

Stop1 Mode

communications will still be accepted and the sensor controller will maintain instantaneous response to all register requests. This

is the only mode in which register values can be set.

This mode is enabled by setting the Configuration Register’s RUNE bit low and DCE bit high.

4.6

Stop2 Mode

this mode.

This mode is enabled by setting the Configuration Register’s RUNE bit low and DCE bit low. The only way to exit this mode is to

toggle the Attention Pin, refer to Section 4.7.

7

6

543210

R

MTP

W

Reset:

0

0

000101

= Unimplemented

Table 10. Master Tick Period Register Field Descriptions

Field

Description

7:0

MTP

Master Tick Period – The Master Tick Period selects or reports the current value of the

touch sensor controller’s primary clock. The resulting period must be in the range 5ms

to 31ms. If the value is outside of this range the MTP will be set to 00011010.

00000000 Encoding 0 – Sets the primary clock multiplier to 5

~

00011010 Encoding 26 - Sets the primary clock multiplier to 31