NUC970 Technical Reference Manual
Publication Release Date: Dec. 15, 2015
- 517 -
Revision V1.30
NUC97
0
T
E
CHNIC
A
L
RE
F
E
RE
N
CE
MA
NUA
L
5.18.3 Block Diagram
The block diagram of I
2
C Serial Interface controller is shown as following.
scl_pad_o/scl_padoen_o
sda_pad_o/sda_padoen_o
i2c_int_o
pclk
preset_n
paddr
pwrite
psel
penable
pwdata
pben
prdata
scl_pad_i
sda_pad_i
I/O
Decoder
Registers
A
M
B
A
A
P
B
I
nt
er
fa
ce
Clock
Prescale
I2C
Core Logic
Figure 5.18-1 I
2
C Block Diagram
NOTE1:
scl_pad_o and
sda_pad_o are always tied to 1’b0.
NOTE2:
scl_padoen_o and sda_padoen_o are active low signals.
5.18.4 Basic Configuration
Before using I
2
C functionality, it
’s necessary to configure I/O pins as the I2C function and enable
I
2
C
’s clock.
Write 0x8 to MFP_GPG0 (SYS_GPG_MFPL[3:0]) and MFP_GPG1 (SYS_GPG_MFPL[7:4])
configures pin PG.0 and PG.1 to be I2C0_SCL and I2C0_SDA respectively.
Write 0x8 to MFP_GPG2 (SYS_GPG_MFPL[11:8]) and MFP_GPG3 (SYS_GPG_MFPL[15:12])
configures pin PG.2 and PG.3 to be I2C1_SCL and I2C1_SDA respectively.
Write 0x8 to MFP_GPH2 (SYS_GPH_MFPL[11:8]) and MFP_GPH3 (SYS_GPH_MFPL[15:12])
configures pin PH.2 and PH.3 to be I2C1_SCL and I2C1_SDA respectively.
Write 0x8 to MFP_GPI3 (SYS_GPI_MFPL[15:12]) and MFP_GPI4 (SYS_GPI_MFPL[19:16])
configures pin PI.3 and PI.4 to be I2C1_SCL and I2C1_SDA respectively.
Please note that configure PG.2, PH.2 and PI.3 to be I2C1_SCL functionality in the same time or
configure PG.3, PH.3 and PI.4 to be I2C1_SDA functionality in the same time is prohibited.