10 Memory Interface
10 – 38
Access
PMS
DMS
BMS
RD
WR
Address
Data
Internal program
high
high
high
high
high
tristated
tristated
memory only
Internal data
high
high
high
high
high
tristated
tristated
memory only
Internal program
high
low
high
low
low
DM address
DM data
memory, external
(for
(for
data memory
read)
write)
Internal data
low
high
high
low
low
PM address
PM data
memory, external
(for
(for
program memory
read)
write)
External boot
high
high
low
low
high
Boot address
Boot data,
memory
(for
Boot page
read)
address
Table 10.5 Pin States During Memory Accesses
Operation
Address
Data
PMS
RD
CLKOUT
SPORTs
BG
DMS
WR
BMS
Reset
tristated
tristated
high
high
active
tristated
high
Booting*
active
active
BMS
active
RD
active
active
tristated
high
after Reset
PMS
,
DMS
WR
high
high
BR
Asserted
tristated
tristated
tristated
tristated
active
active
low
during Normal
Operation, Booting*,
or Go Mode
BR
Asserted
tristated
tristated
tristated
tristated
active
tristated
low
during Reset
Reboot*
active
active
BMS
active
RD
active
active
high
PMS
,
DMS
WR
high
high
active
Table 10.6 Pin States During Reset, Booting*, and Bus Grant
* ADSP-21xx boot memory booting, not ADSP-2181 byte memory booting.