
PSB 7280
Semiconductor Group
37
Data Sheet 1998-07-01
The functions of these registers are described below.
Indirect Access to Configuration and Control Registers
Writing of hardwired registers (configuration and control registers) in the DSP memory
(from 2000
H
to 203F
H
) can be effected through the parallel host interface.
For the last case two directly accessible locations are provided in the DSP/host com area
(host addresses 40
H
and 41
H
). A write operation in the first of these registers with a
command (read/write) and a 6-bit address offset will cause the DSP to read or write a
configuration/control register in address space 2000
H
- 203F
H
. The second location
(host address 41
H
) contains the data read/written from/to the requested location.
The procedure is described in
Table 10
.
3041
H
Reg Data
DSP
→
Host
RDY(LSBit)
Reg Data
Host
→
DSP
Conf/Cont
Reg Address
41
H
Reg Data
Host
→
DSP
Conf/Cont
Reg Address
Reg Data
DSP
→
Host
RDY(LSBit)
3040
H
40
H
DSP
Address
DSP Write
(always
16bit wide)
Reg Data
DSP
→
Host
RDY(LSBit)
DSP Read
(always 16
bit wide)
Reg Data
Host
→
DSP
Conf/Cont
Reg Address
Host
Address
AD0-7
41
H
Host Write
(always 8bit
wide)
Reg Data
Host
→
DSP
Conf/Cont
Reg Address
Host Read
(always 8bit
wide)
Reg Data
DSP
→
Host
RDY(LSBit)
3041
H
3040
H
40
H
Table 9
DSP
Address
Address Mapping of DSP/Host Com Area (Multiplexed Mode)
(cont’d)
DSP Write
(always
16bit wide)
16 bit wide)
AD0-7
DSP Read
(always
Host
Address
Host Write
(always 8bit
wide)
Host Read
(always 8bit
wide)