Datasheet

Rev. I | Page 20 of 68 | July 2010
ADSP-BF534/ADSP-BF536/ADSP-BF537
PIN DESCRIPTIONS
The ADSP-BF534/ADSP-BF536/ADSP-BF537 processors pin
definitions are listed in Table 9. In order to maintain maximum
functionality and reduce package size and pin count, some pins
have dual, multiplexed functions. In cases where pin function is
reconfigurable, the default state is shown in plain text, while the
alternate function is shown in italics. Pins shown with an aster-
isk after their name (*) offer high source/high sink current
capabilities.
All pins are three-stated during and immediately after reset,
with the exception of the external memory interface, asynchro-
nous and synchronous memory control, and the buffered XTAL
output pin (CLKBUF). On the external memory interface, the
control and address lines are driven high, with the exception of
CLKOUT, which toggles at the system clock rate. If BR
is active
(whether or not RESET
is asserted), the memory pins are also
three-stated. During hibernate, all outputs are three-stated
unless otherwise noted in Table 9.
All I/O pins have their input buffers disabled with the exception
of the pins noted in the data sheet that need pull-ups or pull-
downs if unused.
The SDA (serial data) and SCL (serial clock) pins are open drain
and therefore require a pull-up resistor. Consult version 2.1 of
the I
2
C specification for the proper resistor value.
Table 9. Pin Descriptions
Pin Name Type Function
Driver
Type
1
Memory Interface
ADDR19–1 O Address Bus for Async Access A
DATA15–0 I/O Data Bus for Async/Sync Access A
ABE1–0
/SDQM1–0 O Byte Enables/Data Masks for Async/Sync Access A
BR
I Bus Request (This pin should be pulled high when not used.)
BG
OBus Grant A
BGH
O Bus Grant Hang A
Asynchronous Memory Control
AMS3–0
O Bank Select (Require pull-ups if hibernate is used.) A
ARDY I Hardware Ready Control
AOE O Output Enable A
ARE
ORead Enable A
AWE
OWrite Enable A
Synchronous Memory Control
SRAS
O Row Address Strobe A
SCAS
O Column Address Strobe A
SWE
OWrite Enable A
SCKE O Clock Enable(Requires a pull-down if hibernate with SDRAM self-refresh is
used.)
A
CLKOUT O Clock Output B
SA10 O A10 Pin A
SMS
OBank Select A