Choosing Ep Data Mode - Analog Devices SHARC ADSP-21368 Hardware Reference Manual

Processor Pin Descriptions

Choosing EP Data Mode

The / (0, 1, 2, 3) and
FLAG IRQ
Any mode of programming in one group does not affect the other.
Case 1
If 32-bit external SDRAM/FLASH/SRAM is used, then all data pins
should be connected to the memory device so that no other functionality
can be programmed in the data pins. In this case, use MODE 0. If flags
are required, they can be moved to the DPI SRU2.
Case 2
If 16-bit external SDRAM/FLASH/SRAM is used, and if 16 flag inputs
are required, then use MODE 1. Since 16 flags are required, set
/ = 0000. The flag input mode should be specified in the
FLAG PWM_SEL
register.
FLAGS
Case 3
If 16-bit external SDRAM/FLASH/SRAM is used, and if 8 flag outputs
and 8 PWM outputs are required, then use MODE 1. Since 8 flags and
PWM outputs are required, set
are PWM outputs and
DATA31–24
output mode should be specified in
Case 4
If 8-bit external SDRAM/FLASH/SRAM is used, and if 8 flag inputs, 8
flag outputs, and 8 PWM outputs are required, then use MODE 2. Since
16 flags are required, then all flags on
means that there are not enough pins left for the PWM outputs (
). Therefore, program the PWM outputs on
8
on
FLAGS DATA31–24
I/O direction should be specified in the
14-6
DATA31–0
/
FLAG PWM_SEL
DATA23–16
FLAGS
DATA31–16
and . Set
DATA15–8
ADSP-21368 SHARC Processor Hardware Reference
pins are completely independent.
= 1100. (In this mode,
are flag outputs.) The flag
register.
are programmed. This
and program the
DATA23–16
/ = 0011. The flag
FLAGS PWM_SEL
register.
FLAGS
DATA15–