Rohm LAPIS SEMICONDUCTOR ML620Q503, Руководство пользователя

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ML620Q503/Q504 User's Manual
Chapter 15 I
2
C Bus Interface
FEUL620Q504 15–8
15.2.6 I
2
C Bus n Mode Register (I2CnMOD : n=0,1)
Address: 0F748H(I2C0MODL/I2C0MOD), 0F749H(I2C0MODH),
0F758H(I2C1MODL/I2C1MOD), 0F759H(I2C1MODH)
Access: R/W
Access size: 8/16 bits
Initial value: 0200H
7 6 5 4 3 2 1 0
I2CnMODL – – – – I2nDW1 I2nDW0 I2nMD I2nEN
R/W R/W R/W R/W R/W R/W R/W R/W R/W
Initial value 0 0 0 0 0 0 0 0
15 14 13 12 11 10 9 8
I2CnMODH – – – – – – I2nCD1 I2nCD0
R/W R/W R/W R/W R/W R/W R/W R/W R/W
Initial value 0 0 0 0 0 0 1 0
*) I2CnMODH can always read “00H” at the time of I2CnEN=0
I2CnMOD is a special function register (SFR) used to set the operation mode.
Description of Bits
•
I2nEN (bit 0)
The I2nEN bit is used to enable the operation of the I
2
C bus interface. Only when I2nEN is “1”, the
I2nST bit can be set and the I2Cn bus becomes available. When I2nEN is set to “0”, all the SFRs related
to I
2
C bus n (I2CnMODH register is excluded) are initialized.
I2nEN Description
0 Stops I
2
C operation (initial value)
1 Enables I
2
C operation
[Note]
Setting ports should be completed before setting I2nEN to “1”.
•
I2nMD (bit 1)
The I2nMD bit is used to set the communication speed of the I
2
C bus interface. Standard mode or fast
mode can be selected. The communication speed varies depending on the setting value of the SYSC2,
SYSC1, and SYSC0 bits of the frequency control register (FCON0). For details, see “Table 15-1
Relationship between OSCLK and Communication Speeds”.
I2nMD Description
0 Standard mode (initial value)/100 kbps
1 Fast mode/400 kbps
[Note]
This is set so that the communication speed becomes 100kbps/400kbps when the operating frequency
of I
2
C is 4MHz. Set the operating frequency of I
2
C in I2nCD0 and I2nCD1.