RM0312 datasheet(180/275 Pages) STMICROELECTRONICS

180 / 275 page

Inter-integrated circuit (I2C) interface

RM0312

180/275

DocID022352 Rev 3

Master receiver

Following the address transmission and after clearing ADDR, the I2C interface enters

Master Receiver mode. In this mode the interface receives bytes from the SDA line into the

DR register via the internal shift register. After each byte the interface generates in

sequence:

•

An acknowledge pulse if the ACK bit is set

•

The RXNE bit is set and an interrupt is generated if the ITEVTEN and ITBUFEN bits

are set (Figure 69 & Figure 70).

If the RXNE bit is set and the data in the DR register was not read before the end of the next

data reception, the BTF bit is set by hardware and the interface waits for the BTF bit to be

cleared by reading I2C_SR1 and then I2C_DR, stretching SCL low.

Figure 70. Transfer sequence diagram for master receiver

1. Legend:

S= Start, Sr = Repeated Start, P= Stop, A= Acknowledge, NA= Non-acknowledge,

EVx= Event (with interrupt if ITEVTEN=1)

EV5: SB=1, cleared by reading SR1 register followed by writing DR register.

EV6: ADDR=1, cleared by reading SR1 register followed by reading SR3. In 10-bit master receiver mode,

this sequence should be followed by writing CR2 with START = 1.

EV6_1: no associated flag event, used for 1 byte reception only. Program ACK=0 and STOP=1 after

clearing ADDR.

EV7: RXNE=1, cleared by reading DR register.

EV7_1: RXNE=1, cleared by reading DR register, program ACK=0 and STOP request

EV9: ADD10=1, cleared by reading SR1 register followed by writing DR register.

2. If a single byte is received, it is NA.

3. The EV5, EV6 and EV9 events stretch SCL low until the end of the corresponding software sequence.

4. The EV7 event stretches SCL low if the software sequence is not completed before the end of the next byte

reception.

5. The EV7_1 software sequence must be completed before the ACK pulse of the current byte transfer.

7-bit master receiver

10-bit master receiver

Address

Data1

A(1)

Data2

.....

DataN

EV5

EV6

EV7

EV7_1

EV7

Header

Address

EV5

EV9

EV6

Header

Data1

A(1)

.....

EV5

EV6

EV7

Data2

EV7

DataN

EV7_1

EV7

ai17540c

RM0312 датащи(PDF) 180 Page - STMicroelectronics

RM0312 датащи(HTML) 180 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 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

датащи скачать

ссылки URL