Hardware Reference
In-Depth Information
Address Code
(hex)
Register
Data
SPI Read
or Write
Function
Read 7-bit user-definable font data entry from current font
address. MSB of the register data is clear. Font address
pointer is incremented after the read.
0x85
0x00-0x7F
Read
Write 7-bit user-definable font data entry to current font
address. Font address pointer is incremented after the write.
0x05
0x00-0x7F
Write
0x05
0x80-0xFF
Write
Write font address pointer with the register data.
Table 10.11
■
Memory mapping of user-defined font register 0x05
Font Pointer
Address
Action
0x80-0xF6
Valid range to set the font address pointer. Pointer autoincrements after a
font data read or write, while pointer address remains in this range.
0xF7
Font address resets to 0x80 after a font data read or write to this pointer
address.
0xF8 to 0xFF
Invalind range to set the font address pointer. Pointer is set to 0x80.
Table 10.12
■
Font pointer address behavior
The display blinking facility, when enabled, makes the LED drivers flip automatically
between displaying the digit register data in planes P0 and P1. If the digit register data for
any digit is different in two planes, then that digit appears to flip between two characters.
To make a character appear to blink on or off, write the character to one plane and use the
blank character (0x20) for the other plane. Once blinking has been configured, it continues
automatically without further intervention. Blinking is enabled by setting the E bit of the
configuration register.
The blink speed can be programmed to be fast or slow and is determined by the frequency
of the multiplex clock, OSC, and by setting the B bit of the configuration register. The blink
rate selection bit B of the configuration register sets either fast or slow blink speed for the
whole display.
B
LINK
S
YNCHRONIZATION
When multiple digits are displayed, one can choose to synchronize the blinking operation
of these digits. Internally, blink synchronization is achieved by resetting the display multiplex-
ing sequence. As long as all MAX6952s are daisy-chained with one device's DOUT connected
to the DIN of the next device, global synchronization is achieved by toggling the CS pin for
each device, either together or in quick succession.
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