MPR03X

Sensors

Freescale Semiconductor

5

Preliminary

Figure 7. Bit Transfer

2.3.4

Acknowledge

the acknowledge clock pulse, such that the SDA line is stable low during the high period of the clock pulse. When the master is

transmitting to the MPR03X, the MPR03X generates the acknowledge bit, since the MPR03X is the recipient. When the MPR03X

is transmitting to the master, the master generates the acknowledge bit, since the master is the recipient.

Figure 8. Acknowledge

2.3.5

The Slave Address

The MPR03X has a 7-bit long slave address (Figure 9). The bit following the 7-bit slave address (bit eight) is the R/W bit, which

is low for a write command and high for a read command.

Figure 9. Slave Address

The MPR03X monitors the bus continuously, waiting for a START condition followed by its slave address. When a MPR03X

recognizes its slave address, it acknowledges and is then ready for continued communication.

The MPR031 and MPR032 slave addresses are show in Table 2.

Table 2.

Part Number

MPR031

0x4A

MPR032

0x4B

START

CONDITION

SDA

SCL

STOP

CONDITION

P

S

START

CONDITION

SDA

BY TRANSMITTER

S

12

8

9

CLOCK PULSE FOR

ACKNOWLEDGEMENT

SDA

BY RECEIVER

SCL

SDA

1

R/W

ACK

MSB

SCL

01

00

1

0