Cirrus Logic CDB5460AU - Manual (Page 13)

CDB5460AU
DS487DBU1 13
2.4.3 CS5460A Crystal Frequency
The CS5460A accepts a wide range of crystal input frequencies, and can therefore run at many different
sample rates. The crystal frequency being used on the CS5460A should be entered in this box to provide
accurate frequency calculation in the FFT window. This will also help the software decide which functions
the evaluation system can perform reliably.
2.4.4 Configuration Register
In the Configuration Register box, the contents of the Config register can be modified by typing a hexa-
decimal value in the HEX: field, or by changing any of the values below the HEX: field to the desired set-
tings. Although the CDB5460AU software allows the user to modify any of the bits in the Config register,
changing certain bits may cause the software and board to behave erratically. For the evaluation system
to function properly, the Interrupt Output field should be set to the default Active Low. This applies only to
the CDB5460AU evaluation system, and not to the CS5460A chip itself.
2.4.5 Mask Register / Status Register
The Mask Register / Status Register box displays the values for these registers in hexadecimal and de-
codes them to indicate each bit's function. The Mask register can be modified by typing a value in the
HEX: field, or by checking the appropriate check boxes for the bits that are to be masked. The Status reg-
ister cannot be directly modified. It can only be reset by pressing the Clear Status Register button. The
HEX: field for this register and the lamps are indicators only. A lamp which is on means that the corre-
sponding bit in the Status register is set (except the Invalid Command bit, which is inverted). The value
present in the Mask register may be changed by the software during certain operations to provide correct
functionality of the CDB5460AU board.
2.4.6 Cycle Count / PulseRate / Time Base Registers
These fields display the values of corresponding register in both hexadecimal and decimal format. Each
register can be modified by typing a value in the corresponding Value: or HEX: field.
2.4.7 Control Register
The Control Register box is used to make changes to and display the contents of the Ctrl register. The
Ctrl register contains various bits used to activate or terminate various features of the CS5460A. Refer to
the CS5460A data sheet for descriptions of the bits. The user is able to turn each bit on or off individually.
The value of the Ctrl register is displayed in hexadecimal format. Most of the Ctrl register bits are reserved
or unused. Only the usable bits are displayed in the Setup Window.