Motorola MVME5100 Programmer's Reference Manual page 253

2
C Clock Prescaler Register
I
Address
Bit
Name
Operation
READ ZERO
Reset
X
I2_PRESCALE_VAL
2
I C Control Register
Address
Bit
Name
Operation
READ ZERO
Reset
X
i2_start
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$FEF80090
READ ZERO
X
I2_PRESCALE_VAL is a 16-bit register value that will
be used in the following formula for calculating frequency
2
of the I C gated clock signal:
2
I C CLOCK = SYSTEM CLOCK/
(I2_PRESCALE_VAL +1)/2
After power-up, I2_PRESCALE_VAL is initialized to
$1F3 which produces a 100 KHz I
based on a 100.0 MHz system clock. Writes to this
register will be restricted to 4-bytes only.
$FEF80098
READ ZERO
X
2
When set, the I C master controller generates a start sequence
2
on the I C bus on the next write to the I
Register and clears the i2_cmplt bit in the I
After the start sequence and the I
contents have been transmitted, the I
automatically clear the i2_start bit and then set the i2_cmplt
2
bit in the I C Status Register.
Programming Model
I2_PRESCALE_VAL
READ/WRITE
$01F3 P
2
C gated clock signal
READ ZERO
X
2
C Transmitter Data
2
C Status Register.
2
C Transmitter Data Register
2
C master controller will
3
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