9–10
Chapter 9: Using User Flash Memory in MAX II Devices
UFM Operating Modes
The UFM block can also perform stream read operation, reading continuously from
the UFM using the address increment feature. Stream read mode is started by loading
the base address into the address register.
DRSHFT
must then be asserted low at the
first rising edge of
DRCLK
to load data into the data register from the address pointed
to by the address register.
DRSHFT
will then assert high to shift out the 16-bit wide
data with the MSB out first.
shows the UFM control waveforms during
stream read mode.
Figure 9–7.
UFM Read Waveforms
ARShft
ARClk
ARDin
DRShft
DRClk
DRDin
DRDout
OSC_ENA
Program
Erase
Busy
t
ADS
t
DSS
t
DCO
t
DCLK
16 Data Bits
t
DSH
t
ASU
t
ACLK
9 Address Bits t
AH
t
ADH
Figure 9–8.
UFM Stream Read Waveforms
Increment
Address
Increment
Address
ARShft
ARClk
ARDin
DRShft
DRClk
DRDin
DRDout
OSC_ENA
Program
Erase
Busy
9 Address Bits
16 Data Bits
Program
To program or write to the UFM, you must first perform a sequence to load the
reference address into the address register.
DRSHFT
must then be asserted high to load
the data serially into the data register starting with the MSB. Loading an address into
the address register and loading data into the data register can be done concurrently.
After the 16 bits of data have been successfully shifted into the data register, the
PROGRAM
signal must be asserted high to start writing to the UFM. On the rising edge,
the data currently in the data register is written to the location currently in the address
register. The
BUSY
signal is asserted until the program sequence is completed. The
ALTERA [ ALTERA CORPORATION ]
