- SS-HQ1 Application Notes -
Ver.1.0.0 January 7, 2005
69
The SS-HQ1 system does not have a pin for inputting the EEPROM BUSY state. Therefore, the BUSY state is
monitored using a timer, with a WAIT process (10ms or longer) performed each time one word is written.
The timer setting is determined based on 38MHz, which is the fastest of the clock systems selectable by the
SS-HQ1 system. The timer setting is the same regardless of the clock system. Therefore, the write time varies
depending on the selected clock system.
Table 9.2-4 EEPROM BUSY WAIT Time
X’tal frequency
(MHz)
EEPROM BUSY WAIT
(ms)
27.00000 14.7
28.37500 14.0
28.63636 13.9
35.46895 11.2
37.87500 10.5
38.13986 10.4
EEPROM initial recognition process
The EEPROM is initially recognized based on data written to the EEPROM’s 00[h] address.
The following are determined during the initial recognition process:
1. Is communication with the EEPROM possible?
2. What is the EEPROM type (Asahi Kasei or Rohm)?
3. Are valid data written to the EEPROM?
Parameter initialization by EEPROM
Parameters are initialized as follows based on the results of the judgments in the above initial recognition
process.
1. If the EEPROM data are judged to be valid:
EEPROM data are read and parameters are initialized.
2. If the EEPROM data are judged to be invalid:
Parameters are initialized based on the ROM table in the DSP.
In this case, if the port driver (CXD3172AR’s P12 to P15) MODESEL setting does not match the
operating mode, then the operation may not work properly and communication may fail.