I
2
C Module Functional Blocks
MSC8144E Reference Manual, Rev. 3
Freescale Semiconductor
24-3
24.2 I
2
C Module Functional Blocks
The I
2
C module includes the following blocks:
Clock control
Input synchronization
Digital input filter
Transaction monitoring
Arbitration control
Transfer control
In/out data shift register
Address compare
24.2.1 Clock Control
The clock control block handles requests from clock for transferring and controlling data for
multiple tasks. A 9-cycle data transfer (8-bit data plus the ACK bit) clock is requested for the
following conditions:
Initiator mode
— transmit target address after START condition
— transmit target address after restart condition
— transmit data
— receive data
Target mode
— transmit data
— receive data
— receive target address after START or restart condition
24.2.2 Input Synchronization
The input synchronization block synchronizes the input SCL and SDA signals to the CLASS64
clock and detects transitions of these signals.
24.2.3 Digital Input Filter
The SCL and SDA signal inputs are filtered to eliminate noise. Three consecutive signal samples
are compared using a pre-determined sampling rate. If they are all high, the filter output is high.
If they are all low, the output is low. For any high/low combination, the filter output is the value
of the previous clock cycle. The sampling rate is the binary value stored in the frequency register.
The sampling cycle duration is controlled by a down counter that sets a signal at the end of the
count. This allows software to write to the frequency register to control the filtered sampling rate.
Summary of Contents for MSC8144E
Page 1: ...MSC8144E Reference Manual Quad Core Media Signal Processor MSC8144ERM Rev 3 July 2009 ...
Page 48: ...MSC8144E Reference Manual Rev 3 xlviii Freescale Semiconductor ...
Page 86: ...MSC8144E Reference Manual Rev 3 1 38 Freescale Semiconductor Overview ...
Page 168: ...MSC8144E Reference Manual Rev 3 3 60 Freescale Semiconductor External Signals ...
Page 242: ...MSC8144E Reference Manual Rev 3 5 26 Freescale Semiconductor Reset ...
Page 314: ...MSC8144E Reference Manual Rev 3 8 24 Freescale Semiconductor General Configuration Registers ...
Page 414: ...MSC8144E Reference Manual Rev 3 10 14 Freescale Semiconductor MSC8144E SC3400 DSP Subsystem ...
Page 452: ...MSC8144E Reference Manual Rev 3 11 38 Freescale Semiconductor Internal Memory Subsystem ...
Page 520: ...MSC8144E Reference Manual Rev 3 12 68 Freescale Semiconductor DDR SDRAM Memory Controller ...
Page 1070: ...MSC8144E Reference Manual Rev 3 21 28 Freescale Semiconductor Timers ...