Motorola MCF5282 Chip Select Control Registers CSCR0-CSCR6, 8describes CSCRn fields, Sd,Uc

Models: MCF5282 MCF5281

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Chip Select Registers

 

 

 

 

Table 12-7. CSMRn Field Descriptions (continued)

 

 

 

 

 

Bits

Name

 

 

Description

 

 

 

5–1

C/I, SC,

Address space mask bits. These bits determine whether the specified accesses can occur to the

 

SD,UC,

address space defined by the BAM for this chip select.

 

UD

C/I

CPU space and interrupt acknowledge cycle mask

 

 

 

 

SC

Supervisor code address space mask

 

 

SD

Supervisor data address space mask

 

 

UC

User code address space mask

 

 

UD

User data address space mask

 

 

0 The address space assigned to this chip select is available to the specified access type.

 

 

1 The address space assigned to this chip select is not available (masked) to the specified access

 

 

 

type. If this address space is accessed, chip select is not activated and a regular external bus

 

 

 

cycle occurs.

 

 

Note that if AM = 0, SC, SD, UC, and UD are ignored in the chip select decode on DMA access.

 

 

 

0

V

Valid bit. Indicates whether the corresponding CSAR, CSMR, and CSCR contents are valid.

 

 

Programmed chip selects do not assert until V is set (except for CS0, which acts as the global chip

 

 

select). Reset clears each CSMRn[V].

 

 

0

Chip select invalid

 

 

1

Chip select valid

 

 

 

 

 

12.4.1.3 Chip Select Control Registers (CSCR0–CSCR6)

Each CSCR, shown in Figure 12-4,controls the auto-acknowledge, port size, burst capability, and activation of each chip select. Note that to support the external boot chip select, CS0, the CSCR0 reset values differ from the other CSCRs. CS0 allows address decoding for boot ROM before system initialization.

15

14

13

10

9

8

7

6

5

4

3

 

2

0

Field

 

WS

 

AA

 

PS1

PS0

BEM

BSTR

BSTW

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset: CSCR0

 

11_11

 

1

 

D19

D18

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Reset: Other CSCRs

 

 

 

 

 

Uninitialized

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

R/W

 

 

 

 

 

 

R/W

 

 

 

 

 

 

 

 

 

 

 

 

Address

 

 

0x08A (CSCR0); 0x096 (CSCR1); 0x0A2 (CSCR2); 0x0AE (CSCR3);

 

 

 

 

0x0BA (CSCR4); 0x0C6 (CSCR5); 0x0D2 (CSCR6)

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Figure 12-4. Chip Select Control Registers (CSCRn)

Table 12-8describes CSCRn fields.

12-8

MCF5282 User’s Manual

MOTOROLA

Page 262
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Motorola MCF5282, MCF5281 Chip Select Control Registers CSCR0-CSCR6, 8describes CSCRn fields, Sd,Uc, PS1 PS0 BEM Bstr Bstw