
DS4830A User’s Guide
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10.2.5 – I
2
C Master Clock Control Register (I2CCK_M)
I
2
C Clock High Period. These bits define the high period of the I
2
C clock. This period is defined
by the number of system clocks. The high time duration is calculated using the following equation:
I
2
C High Time Period = System Clock Period x (I2CCKH[7:0] + 1)
I2CCKH[7:0] must be set to a minimum value of 2 to ensure proper operation. Any value less than 2
I
2
C Clock Low Period. These bits define the low period of the I
2
C clock. This period is defined by
the number of system clocks. The low time duration is calculated using the following equation:
I
2
C Low Time Period = System Clock Period x (I2CCKL[7:0] + 1)
I2CCKL[7:0] must be set to a minimum value of 4 to ensure proper operation. Any value less than 4
is set to 4.
10.2.6 – I
2
C Master Timeout Register (I2CTO_M)
The I2CTO_M register determines the length of the timeout interval. The timeout interval is defined by the number of I
2
C bit
periods (SCL high + SCL low). When cleared to 00h, the timeout function is disabled. When set to any other value, the I
2
C
controller waits until the timeout expires and sets the I2CTOI flag. The timeout period is:
I
2
C Timeout = I
2
C Bit Rate x (I2CTO[7:0] + 1)
The timeout timer resets to 0 and starts to count after each of the following events.
• The I2CSTART bit is set.
• The I2CSTOP bit is set.
• Any time that SCL goes low.
10.2.7 – I
2
C Slave Address Register (I2CSLA_M and I2CSLA2_M)
These register have no function when operating in master mode and are used in slave mode to program the slave
address.
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