LM3S102-IRN20 Luminary Micro, Inc., LM3S102-IRN20 Datasheet - Page 272

• Manufacturer Part Number: LM3S102-IRN20
• Description: Microcontroller
• Manufacturer: Luminary Micro, Inc.

Inter-Integrated Circuit (I2C) Interface
Figure 13-13. Slave Command Sequence
13.2.2
272
Available Speed Modes
The SCL clock rate is determined by the parameters: CLK_PRD, TIMER_PRD, SCL_LP, and
SCL_HP.
where:
CLK_PRD
SCL_LP
SCL_HP
TIMER_PRD
page 282).
The SCL clock period is calculated as follows:
SCL_PERIOD = 2*(1 + TIMER_PRD)*(SCL_LP + SCL_HP)*CLK_PRD
For example:
CLK_PRD = 50 ns
TIMER_PRD = 2
SCL_LP=6
SCL_HP=4
yields a SCL frequency of:
1/T = 333 Khz
is the Low phase of the SCL clock (fixed at 6)
is the High phase of the SCL clock (fixed at 4)
is the system clock period
is the programmed value in the I2C Master Timer Period (I2CMTPR) register (see
address to I2CSOAR
write OWN Slave
write “-------1”
to I2CSCSR
N
N
read I2CSCSR
Idle
write Data to
RREQ=”1”
TREQ=”1”
I2CSDR
Preliminary
Y
Y
read Data from
I2CSDR
October 6, 2006