NXP Semiconductors
UM10858
PN7462 family HW user manual
UM10858
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User manual
COMPANY PUBLIC
Rev. 1.4 — 14 May 2018
314514
238 of 345
14.1.7 External wiring
The I2C controller operates on an external clock. For proper operation, external blocks
must supply a clock signal to the apb_clk pin. Furthermore, as can be seen in
, the
analog characteristics of the I2C bus (data and clock are connected to pull-up resistors)
cause that the SCL and SDA lines must be driven by a pull-down circuit also called “I2C”.
The signals scl_out and sda_out are then used to enable the pull-down circuit (when ‘0’)
or disable it when ‘1’.
Fig 45. I2C external wiring diagram
14.1.8 I2C Register overview
Table 275. I2CM Register overview (base address 0x4003 0000)
Name
Address
offset
Width
(bits)
Access Reset value
Description
CONFIG_REG
[1]
0x0000 32
RW
0x00000000
Register fields to configure the I2C Master &
I2C (Transmission/Reception) mode of
operation.
BAUDRATE_REG
[1]
0x0004
32
RW
0x000000F4
Register field to generate the I2C Serial Clock
Frequency. Default: 1 MHz Serial Clock
Frequency at input system/IP Clock
Frequency of 27 MHz
SDA_HOLD_REG
[1]
0x0008
32
RW
0x00000009
Used to set the SDA hold time (SDA
generation with respect to falling edge on
SCL) - Must be set to 0x00 when operating in
Fast-mode Plus (freq SCL> 400 kHz)
I2C_ADDRESS_REG
[1]
0x000C
32
RW
0x0000002A
Contains the I2C Slave address of the device.
FIFO_THRESHOLD_REG
0x0010
32
RW
0x00000701
Register field to set the FIFO Threshold Level
for the Interrupt Request Generation
BYTECOUNT_CONFIG_REG
0x0014
32
RW
0x00000000
Register bit field to configure the number of
bytes to be transmitted or received