Nations Technologies Inc.
Tel
:
+86-755-86309900
:
Address: Nations Tower, #109 Baoshen Road, Hi-tech Park North.
Nanshan District, Shenzhen, 518057, P.R.China
452
/
631
Bit field
Name
Description
0
:
Tlow/Thigh = 2
;
1
:
Tlow/Thigh = 16/9
13:12
Reserved
Reserved, the reset value must be maintained.
11:0
CLKCTRL[11:0]
Clock control register in Fast/Standard mode (Master mode)
This division factor is used to set the SCL clock in the master mode.
If duty cycle = Tlow/Thigh = 1/1:
CLKCTRL = f
PCLK1
(Hz)/100000/2
Tlow = CLKCTRL×T
PCLK1
Thigh = CLKCTRL×T
PCLK1
If duty cycle = Tlow/Thigh = 2/1:
CLKCTRL = f
PCLK1
(Hz)/100000/3
Tlow = 2 ×CLKCTRL×TPCLK1
Thigh = CLKCTRL×T
PCLK1
If duty cycle = Tlow/Thigh = 16/9:
CLKCTRL = f
PCLK1
(Hz)/100000/25
Tlow = 16 ×CLKCTRL×T
PCLK1
Thigh = 9 ×CLKCTRL×T
PCLK1
For example, if f
PCLK1
(Hz) = 8MHz, duty cycle = 1/1, CLKCTRL = 8000000/100000/2 = 0x28.
Note: 1. The minimum setting value is 0x04 in standard mode and 0x01 in fast mode;
2. T
high
= T
r(SCL)
+T
w(SCLH)
. See the definitions of these parameters in the data sheet for details.
3. T
low
= T
f(SCL)
+T
w(SCLL)
, see the definitions of these parameters in the data sheet for details;
4. These delays have no filters;
I2C Rise time register (I2C_TMRISE)
Address offset: 0x20
Reset value: 0x0002
Note: The I2C_TMRISE register function is only valid in master mode. changed when I2C is disabled
(I2C_CTRL1.EN=0).
Bit field
Name
Description
15:6
Reserved
Reserved, the reset value must be maintained.
5:0
TMRISE[5:0]
Maximum rise time in fast/standard mode (master mode).
These bits must be set to the maximum SCL rising time given in the I2C bus specification, and
incremented step is 1.
For example, the maximum allowable SCL rise time in standard mode is 1000ns. if the value in
I2C_CTRL2.CLKFREQ [5:0] is equal to 0x08 and TPCLK1=125ns ,09h(1000ns/125 ns + 1) must
be written in TMRISE[5:0] ,.