Datasheet

ADSP-BF531/ADSP-BF532/ADSP-BF533
Rev. I | Page 5 of 64 | August 2013
The second on-chip memory block is the L1 data memory, con-
sisting of one or two banks of up to 32K bytes. The memory
banks are configurable, offering both cache and SRAM func-
tionality. This memory block is accessed at full processor speed.
The third memory block is a 4K byte scratchpad SRAM, which
runs at the same speed as the L1 memories, but is only accessible
as data SRAM and cannot be configured as cache memory.
External (Off-Chip) Memory
External memory is accessed via the external bus interface unit
(EBIU). This 16-bit interface provides a glueless connection to a
bank of synchronous DRAM (SDRAM) as well as up to four
banks of asynchronous memory devices including flash,
EPROM, ROM, SRAM, and memory mapped I/O devices.
The PC133-compliant SDRAM controller can be programmed
to interface to up to 128M bytes of SDRAM. The SDRAM con-
troller allows one row to be open for each internal SDRAM
bank, for up to four internal SDRAM banks, improving overall
system performance.
The asynchronous memory controller can be programmed to
control up to four banks of devices with very flexible timing
parameters for a wide variety of devices. Each bank occupies a
1M byte segment regardless of the size of the devices used, so
that these banks are only contiguous if each is fully populated
with 1M byte of memory.
I/O Memory Space
Blackfin processors do not define a separate I/O space. All
resources are mapped through the flat 32-bit address space.
On-chip I/O devices have their control registers mapped into
memory mapped registers (MMRs) at addresses near the top of
the 4G byte address space. These are separated into two smaller
blocks, one containing the control MMRs for all core functions,
and the other containing the registers needed for setup and con-
trol of the on-chip peripherals outside of the core. The MMRs
are accessible only in supervisor mode and appear as reserved
space to on-chip peripherals.
Booting
The ADSP-BF531/ADSP-BF532/ADSP-BF533 processors con-
tain a small boot kernel, which configures the appropriate
peripheral for booting. If the processors are configured to boot
from boot ROM memory space, the processor starts executing
from the on-chip boot ROM. For more information, see Boot-
ing Modes on Page 14.
Figure 2. Blackfin Processor Core
SEQUENCER
ALIGN
DECODE
LOOP BUFFER
16
16
8888
40 40
A0 A1
BARREL
SHIFTER
DATA ARITHMETIC UNIT
CONTROL
UNIT
R7.H
R6.H
R5.H
R4.H
R3.H
R2.H
R1.H
R0.H
R7.L
R6.L
R5.L
R4.L
R3.L
R2.L
R1.L
R0.L
ASTAT
40 40
32
32
32
32
32
32
32LD0
LD1
SD
DAG0
DAG1
ADDRESS ARITHMETIC UNIT
I3
I2
I1
I0
L3
L2
L1
L0
B3
B2
B1
B0
M3
M2
M1
M0
SP
FP
P5
P4
P3
P2
P1
P0
DA1
DA0
32
32
32
PREG
RAB
32
TO MEMORY