DSP56853 Datasheet, PDF (79/662 Pages) Freescale Semiconductor, Inc – Digitial Signal Controller

Power, Ground and Peripheral Signals
Table 2-3. Grounds
Signal Name
Signal Description
853 854 855 857 858
Pins Pins Pins Pins Pins
V_SS
V_SSIO
V_SSA
Ground—These pins provide grounding for the internal structures of
the chip and should all be attached to V_SS.
66458
Ground—These pins provide grounding for all I/O and ESD structures
of the chip. They all should be attached to V_SSIO.
10 10 10 12 14
Analog Power—These pins supply an analog ground.
11122
Table 2-4. External Bus Control Signals
Signal Name Signal Type
Signal Description
A0-A20
D0-D15
RD
WR
Output(Z)
Address Bus—These signals specify a word
address for external program or data memory
access.
Data Bus—These pins provide the bidirectional
Input / Output(Z) data for external program or data memory
accesses.
Output
Read Enable—is asserted during external
memory read cycles. This signal is pulled high
during reset.
Output
Write Enable—is asserted during external
memory write cycles. This signal is pulled high
during reset.
853 854 855 857 858
Pins Pins Pins Pins Pins
21 21 21 — 21
16 16 16 — 16
1 1 1—1
1 1 1—1
Table 2-5. External Chip Select
Signal Name Signal Type
Signal Description
853 854 855 857 858
Pins Pins Pins Pins Pins
CSO- CS3
Output
External Chip Select—These pins are used as
chip selects during external memory cycles.
44444
(GPIOA0-A3) Input / Output Port A GPIO0-3—These are General Purpose I/O
pins when not configured for EMI use.
Freescale Semiconductor
Overview, Rev. 4
2-11