VisualDSP++ 4.5 Loader and Utilities Manual - Analog Devices

ADSP-21161 Processor Booting
Boot Mode Selection
The state of the LBOOT, EBOOT, and BMS pins selects the ADSP-21161 processor’s
boot mode. Table 4-1 and Table 4-2 show how the pin states
correspond to the modes.
Table 4-1. ADSP-21161 Boot Mode Pins
Pin Type Description
EBOOT I EPROM boot – when EBOOT is high, the processor boot-loads from an 8-bit
EPROM through the processor’s external port. When EBOOT is low, the LBOOT
and BMS pins determine booting mode.
LBOOT I Link port boot – when LBOOT is high and EBOOT is low, the processor boots
from another SHARC processor through the processor’s link port. When
LBOOT is low and EBOOT is low, the processor boots from a host processor
through the processor’s external port.
BMS I/O/T 1
Boot memory select – when boot-loading from EPROM (EBOOT=1 and
LBOOT=0), the pin is an output and serves as the chip select for the EPROM. In
a multiprocessor system, BMS is output by the bus master. When host-booting,
link-booting, or SPI-booting (EBOOT=0), BMS is an input and must be high.
1 Three-statable in EPROM boot mode (when BMS is an output).
Table 4-2. ADSP-21161 Boot Mode Pin States
EBOOT LBOOT BMS Booting Mode
1 0 Output EPROM (connects BMS to EPROM chip select)
0 0 1 (Input) Host processor
0 1 1 (Input) Link port
0 1 0 (Input) Serial port (SPI)
0 0 0 (Input) No-boot (processor executes from external memory)
4-4 VisualDSP++ 4.5 Loader and Utilities Manual