MSC8144E Reference Manual, Rev. 3
5-10
Freescale
Semiconductor
Reset
5.2.7.1.1 Using The Boot Sequencer For Reset Configuration
Note:
For detailed description about the I
2
C interface and the boot sequencer, refer to
When used to load the reset configuration words, the I
2
C module addresses the first EEPROM,
reads the preamble, and then reads the first two data structures. The device latches the reset
configuration words internally and the I
2
C module enters its reset state until
HRESET
is
deasserted. There should be no other I
2
C traffic when the boot sequencer is active. After
HRESET
is deasserted, the boot sequencer mode is disabled.
Note:
I
2
C SCL clock stretching is not allowed during the reset sequence. The SCL signal
should have minimum rise/fall times.
5.2.7.1.2 EEPROM Addressing
A reset initiator MSC8144E is selected by holding the STOP_BS signal low during the power-on
reset flow. The reset initiator uses 0b1010000 for the EEPROM calling address. A reset target
uses 0b1010111 for the EEPROM calling address. The EEPROM to be addressed must contain
the reset configuration information and be programmed to respond to the 0b1010000 address.
The EEPROM device must have address inputs connected to GND in multi device reset
applications. No additional EEPROMs are accessed by the boot sequencer in reset configuration
mode. See also Section 5.2.7.2, Loading Multiple Devices From a Single I
5.2.7.1.3 EEPROM Data Format In Reset Configuration Mode
The I
2
C module expects a specific data format in the EEPROM. The first three bytes should be
the preamble and should contain a value of 0xAA55AA. The I
2
C module verifies that this
preamble is correctly detected before proceeding further. The two reset configuration words,
should follow the preamble and should use the required format provided in Section 6.5.2.3, Boot
File Format, on page 6-17. Within each configuration word, the first 3 bytes are reserved and
must contain the value 0xFFFFFF. After the first 3 bytes, 4 bytes of data should hold the desired
value of the reset configuration word. The boot sequencer assumes that a big endian address is
stored in the EEPROM. If a preamble fail or any other I
2
C bus error is detected, the device stops
processing and remains in a hard reset state with
HRESET
asserted. The MSC8144E drives
RC_LDF
low (asserted) for half a
CLKIN
cycle to indicate an error. Then the MSC8144E resumes
reading the RCW. This flow may repeat until no error id is detected.
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 ...