Expansion Bus Registers
8-7
Expansion Bus
8.3.1
Expansion Bus Host Port Registers
The external master on the expansion bus uses the XCNTL signal to select
which internal register is being accessed. The state of this pin selects whether
access is made to the expansion bus internal slave address (XBISA) register
or, expansion bus data (XBD) register. In addition to that, the external master
has access to the entire memory map of the DSP, including memory-mapped
registers.
Table 8–3 summarizes the registers that the expansion bus host port uses for
communication between the host device and the CPU.
Table 8–3. Expansion Bus Host Port Registers
Register
Abbreviation
Register
Name
Host Read/
Write Access
‘C6202 Read/
Write Access
Memory
Mapped
Address
XBHC
Expansion
Bus Host
Port Control
—
RW
0x0188 000C
XBEA
Expansion
Bus External
Address
—
RW
0x0188 0024
XBIMA
Expansion
Bus Internal
Master
Address
—
RW
0x0188 0020
XBISA
Expansion
Bus Internal
Slave Address
RW
—
XBD
Expansion
Bus Data
RW
—