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PIC18F2455/2550/4455/4550

FIGURE 28-15: I2C™ BUS START/STOP BITS TIMING

SCL

93

91

90

92

SDA

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Start

 

 

Stop

Condition

Condition

Note: Refer to Figure 28-4 for load conditions.

TABLE 28-19: I2C™ BUS START/STOP BITS REQUIREMENTS (SLAVE MODE)

Param.

Symbol

Characteristic

Min

Max

Units

Conditions

No.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

90

TSU:STA

Start Condition

100 kHz mode

4700

ns

Only relevant for Repeated

 

 

 

 

 

 

 

Start condition

 

 

Setup Time

400 kHz mode

600

 

 

 

 

 

 

 

 

 

 

 

 

 

91

THD:STA

Start Condition

100 kHz mode

4000

ns

After this period, the first

 

 

 

 

 

 

 

clock pulse is generated

 

 

Hold Time

400 kHz mode

600

 

 

 

 

 

 

 

 

 

 

 

 

 

92

TSU:STO

Stop Condition

100 kHz mode

4700

ns

 

 

 

 

 

 

 

 

 

 

 

Setup Time

400 kHz mode

600

 

 

 

 

 

 

 

 

 

 

93

THD:STO

Stop Condition

100 kHz mode

4000

ns

 

 

 

 

 

 

 

 

 

 

 

Hold Time

400 kHz mode

600

 

 

 

 

 

 

 

 

 

 

FIGURE 28-16: I2C™ BUS DATA TIMING

103

100

102

101

SCL

 

90

107

106

91

92

SDA

In

 

110

109

109

SDA

Out

Note: Refer to Figure 28-4 for load conditions.

DS39632D-page 390

Preliminary

2007 Microchip Technology Inc.

PIC18F2455/2550/4455/4550

TABLE 28-20: I2C™ BUS DATA REQUIREMENTS (SLAVE MODE)

Param.

Symbol

Characteristic

Min

Max

Units

Conditions

No.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

100

THIGH

Clock High Time

100 kHz mode

4.0

μs

PIC18FXXXX must operate

 

 

 

 

 

 

 

at a minimum of 1.5 MHz

 

 

 

 

 

 

 

 

 

 

 

400 kHz mode

0.6

μs

PIC18FXXXX must operate

 

 

 

 

 

 

 

at a minimum of 10 MHz

 

 

 

 

 

 

 

 

 

 

 

MSSP Module

1.5 TCY

 

 

 

 

 

 

 

 

 

 

101

TLOW

Clock Low Time

100 kHz mode

4.7

μs

PIC18FXXXX must operate

 

 

 

 

 

 

 

at a minimum of 1.5 MHz

 

 

 

 

 

 

 

 

 

 

 

400 kHz mode

1.3

μs

PIC18FXXXX must operate

 

 

 

 

 

 

 

at a minimum of 10 MHz

 

 

 

 

 

 

 

 

 

 

 

MSSP Module

1.5 TCY

 

 

 

 

 

 

 

 

 

 

102

TR

SDA and SCL Rise

100 kHz mode

1000

ns

 

 

 

Time

 

 

 

 

 

 

 

400 kHz mode

20 + 0.1 CB

300

ns

CB is specified to be from

 

 

 

 

 

 

 

 

 

 

10 to 400 pF

 

 

 

 

 

 

 

 

103

TF

SDA and SCL Fall

100 kHz mode

300

ns

 

 

 

Time

 

 

 

 

 

 

 

400 kHz mode

20 + 0.1 CB

300

ns

CB is specified to be from

 

 

 

 

 

 

 

 

 

 

10 to 400 pF

 

 

 

 

 

 

 

 

90

TSU:STA

Start Condition

100 kHz mode

4.7

μs

Only relevant for Repeated

 

 

Setup Time

 

 

 

 

Start condition

 

 

400 kHz mode

0.6

μs

91

THD:STA

Start Condition

100 kHz mode

4.0

μs

After this period, the first

 

 

Hold Time

400 kHz mode

0.6

μs

clock pulse is generated

 

 

 

 

 

 

 

 

106

THD:DAT

Data Input Hold

100 kHz mode

0

ns

 

 

 

Time

 

 

 

 

 

 

 

400 kHz mode

0

0.9

μs

 

107

TSU:DAT

Data Input Setup

100 kHz mode

250

ns

(Note 2)

 

 

Time

 

 

 

 

 

 

 

400 kHz mode

100

ns

 

 

 

 

 

 

 

 

 

 

 

 

 

92

TSU:STO

Stop Condition

100 kHz mode

4.7

μs

 

 

 

Setup Time

400 kHz mode

0.6

μs

 

 

 

 

 

 

 

 

 

109

TAA

Output Valid from

100 kHz mode

3500

ns

(Note 1)

 

 

Clock

 

 

 

 

 

 

 

400 kHz mode

ns

 

 

 

 

 

 

 

 

 

 

 

 

 

110

TBUF

Bus Free Time

100 kHz mode

4.7

μs

Time the bus must be free

 

 

 

 

 

 

 

before a new transmission

 

 

 

400 kHz mode

1.3

μs

 

 

 

 

 

 

 

can start

D102

CB

Bus Capacitive Loading

400

pF

 

 

 

 

 

 

 

 

 

Note 1: As a transmitter, the device must provide this internal minimum delay time to bridge the undefined region (min. 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions.

2:A Fast mode I2C™ bus device can be used in a Standard mode I2C bus system but the requirement, TSU:DAT ≥ 250 ns, must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must

output the next data bit to the SDA line, TR max. + TSU:DAT = 1000 + 250 = 1250 ns (according to the Standard mode I2C bus specification), before the SCL line is released.

2007 Microchip Technology Inc.

Preliminary

DS39632D-page 391

PIC18F2455/2550/4455/4550

FIGURE 28-17: MASTER SSP I2C™ BUS START/STOP BITS TIMING WAVEFORMS

SCL

93

91

90

92

SDA

Start

Stop

Condition

Condition

Note: Refer to Figure 28-4 for load conditions.

TABLE 28-21: MASTER SSP I2C™ BUS START/STOP BITS REQUIREMENTS

Param.

Symbol

Characteristic

Min

Max

Units

Conditions

No.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

90

TSU:STA

Start Condition

100 kHz mode

2(TOSC)(BRG + 1)

ns

Only relevant for

 

 

 

 

 

 

 

Repeated Start

 

 

Setup Time

400 kHz mode

2(TOSC)(BRG + 1)

 

 

 

 

condition

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

2(TOSC)(BRG + 1)

 

 

 

 

 

 

91

THD:STA

Start Condition

100 kHz mode

2(TOSC)(BRG + 1)

ns

After this period, the

 

 

 

 

 

 

 

first clock pulse is

 

 

Hold Time

400 kHz mode

2(TOSC)(BRG + 1)

 

 

 

 

generated

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

2(TOSC)(BRG + 1)

 

 

 

 

 

 

92

TSU:STO

Stop Condition

100 kHz mode

2(TOSC)(BRG + 1)

ns

 

 

 

 

 

 

 

 

 

 

 

Setup Time

400 kHz mode

2(TOSC)(BRG + 1)

 

 

 

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

2(TOSC)(BRG + 1)

 

 

93

THD:STO

Stop Condition

100 kHz mode

2(TOSC)(BRG + 1)

ns

 

 

 

 

 

 

 

 

 

 

 

Hold Time

400 kHz mode

2(TOSC)(BRG + 1)

 

 

 

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

2(TOSC)(BRG + 1)

 

 

Note 1:

Maximum

pin capacitance =

10 pF for all I2C™ pins.

 

 

 

FIGURE 28-18: MASTER SSP I2C™ BUS DATA TIMING

103

 

 

 

 

 

100

 

 

 

 

 

102

 

 

 

 

101

SCL

 

 

90

106

 

91

107

92

SDA

In

109

109

110

SDA

Out

Note: Refer to Figure 28-4 for load conditions.

DS39632D-page 392

Preliminary

2007 Microchip Technology Inc.

PIC18F2455/2550/4455/4550

TABLE 28-22: MASTER SSP I2C™ BUS DATA REQUIREMENTS

Param.

Symbol

Characteristic

Min

Max

Units

Conditions

No.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

100

THIGH

Clock High Time

100 kHz mode

2(TOSC)(BRG + 1)

ms

 

 

 

 

 

 

 

 

 

 

 

 

400 kHz mode

2(TOSC)(BRG + 1)

ms

 

 

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

2(TOSC)(BRG + 1)

ms

 

101

TLOW

Clock Low Time

100 kHz mode

2(TOSC)(BRG + 1)

ms

 

 

 

 

 

 

 

 

 

 

 

 

400 kHz mode

2(TOSC)(BRG + 1)

ms

 

 

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

2(TOSC)(BRG + 1)

ms

 

102

TR

SDA and SCL

100 kHz mode

1000

ns

CB is specified to be from

 

 

Rise Time

 

 

 

 

10 to 400 pF

 

 

400 kHz mode

20 + 0.1 CB

300

ns

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

300

ns

 

103

TF

SDA and SCL

100 kHz mode

300

ns

CB is specified to be from

 

 

Fall Time

 

 

 

 

10 to 400 pF

 

 

400 kHz mode

20 + 0.1 CB

300

ns

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

100

ns

 

90

TSU:STA

Start Condition

100 kHz mode

2(TOSC)(BRG + 1)

ms

Only relevant for

 

 

Setup Time

 

 

 

 

Repeated Start

 

 

400 kHz mode

2(TOSC)(BRG + 1)

ms

 

 

 

condition

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

2(TOSC)(BRG + 1)

ms

 

 

 

 

91

THD:STA

Start Condition

100 kHz mode

2(TOSC)(BRG + 1)

ms

After this period, the first

 

 

Hold Time

 

 

 

 

clock pulse is generated

 

 

400 kHz mode

2(TOSC)(BRG + 1)

ms

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

2(TOSC)(BRG + 1)

ms

 

106

THD:DAT

Data Input

100 kHz mode

0

ns

 

 

 

Hold Time

 

 

 

 

 

 

 

400 kHz mode

0

0.9

ms

 

 

 

 

 

 

 

 

 

 

 

 

 

107

TSU:DAT

Data Input

100 kHz mode

250

ns

(Note 2)

 

 

Setup Time

 

 

 

 

 

 

 

400 kHz mode

100

ns

 

 

 

 

 

 

 

 

 

 

 

 

 

92

TSU:STO

Stop Condition

100 kHz mode

2(TOSC)(BRG + 1)

ms

 

 

 

Setup Time

 

 

 

 

 

 

 

400 kHz mode

2(TOSC)(BRG + 1)

ms

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

2(TOSC)(BRG + 1)

ms

 

109

TAA

Output Valid

100 kHz mode

3500

ns

 

 

 

from Clock

 

 

 

 

 

 

 

400 kHz mode

1000

ns

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 MHz mode(1)

ns

 

110

TBUF

Bus Free Time

100 kHz mode

4.7

ms

Time the bus must be free

 

 

 

 

 

 

 

before a new transmission

 

 

 

400 kHz mode

1.3

ms

 

 

 

can start

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

D102

CB

Bus Capacitive Loading

400

pF

 

 

 

 

 

 

 

 

Note 1:

Maximum

pin capacitance = 10 pF for all I2

C™ pins.

 

 

 

2:A Fast mode I2C bus device can be used in a Standard mode I2C bus system but parameter #107 250 ns must then be met. This will automatically be the case if the device does not stretch the LOW period of the SCL signal. If such a device does stretch the LOW period of the SCL signal, it must output the next data bit to the SDA line, parameter #102 + parameter #107 = 1000 + 250 = 1250 ns (for 100 kHz mode), before the SCL line is released.

2007 Microchip Technology Inc.

Preliminary

DS39632D-page 393

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