Motorola DSP96002 User Manual page 96

ment that is defined as internal remains internal. The Port Select Register format is shown in Figure 7-6 and
is described below.
31 24 23
X X X X X X X X Y Y Y Y Y Y Y Y P P P P P P P P
* 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0 7 6 5 4 3 2 1 0
* - reserved, read as zeros, should be written with
zeros for future compatibility.
$FFFFFF7F
$E0000000
$C0000000
$A0000000
$80000000
$60000000
$40000000
$20000000
$00000800
or
$00000200
Note: X and Y Data Memories lowest external address determined by DE bit in the OMR register. P
Memory lowest external address determined by MA, MB and MC bits in the OMR register.
Figure 7-6. DSP96002 Port Select Register (PSR)
7.3.1.1 PSR Program Memory Port Select (P0-P7) Bits 0-7
The Program Memory Port Select control bits (P0-P7) determine the assignment of the 8 Program Memory
segments to Port A or B. If the segment bit is cleared, the Program Memory segment is assigned to Port A.
If the segment bit is set, the memory segment is assigned to Port B. The memory segment to control bit
correlation is shown in Figure 7-6. For example, if the P4 bit is set, then all memory traffic for addresses
P:$80000000 to P:$9FFFFFFF will go thorough Port B. During hardware reset, the P0-P7 bits are cleared
if the MODA pin was hold low when negating
—
high when negating R
7.3.1.2 PSR Y Data Memory Port Select (Y0-Y7) Bits 8-15
The Y Data Memory Port Select control bits (Y0-Y7) determine the assignment of the 8 Y Data Memory seg-
ments to Port A or B. If the segment bit is cleared, the Y Data Memory segment is assigned to Port A. If the
segment bit is set, the memory segment is assigned to Port B. The memory segment to control bit correla-
tion is shown in Figure 7-6. For example, if the Y4 bit is set, then all memory traffic for addresses
Y:$80000000 to Y:$9FFFFFFF will go thorough Port B. During hardware reset, the Y0-Y7 bits are cleared.
7 - 10
16 15
X
$FFFFFFFF
X7
$E0000000
X6
$C0000000
X5
$A0000000
X4
$80000000
X3
$60000000
X2
$40000000
X1
$20000000
X0
$00000800
or
$00000200
—
— — — –
E S E T.
DSP96002 USER'S MANUAL
8 7
Y
$FFFFFFFF
Y7
$E0000000
Y6
$C0000000
Y5
$A0000000
Y4
$80000000
Y3
$60000000
Y2
$40000000
Y1
$20000000
Y0
$00000400
$00000000
— — — –
R E S E T. P0-P7 are set if the MODA pin was hold
0 PSR
Port Select
Register
X:$FFFFFFFC
P
P7
P6
P5
P4
P3
P2
P1
P0
or
MOTOROLA