Epson ARM720T Manuel D’Utilisation

HBURST[2:0] indicates the type of burst generated by the ARM720T core, as shown in 

Table 6-3.

For more details of burst operation, see the 

AMBA Specification (Rev 2.0)

.

HPROT[3:0] is the protection control bus. These signals provide additional information about 

a bus access and are primarily intended to enable a module to implement an access permission 

scheme. 
These signals indicate whether the transfer is:

•

an opcode fetch or data access

•

a privileged-mode access or User-mode access.

For bus masters with a memory management unit, these signals also indicate whether the 

current access is cachable or bufferable. 
Table 6-4 shows the protection control encodings as produced from the ARM720T core.

Some bus masters are not capable of generating accurate protection information, so it is 

recommended that slaves do not use the HPROT[3:0] signals unless strictly necessary.

Table 6-3  Burst type encodings

b000

SINGLE

Single transfer

b001 

INCR

Incrementing burst of 
unspecified length

b101

INCR8

8-beat incrementing burst

Table 6-4  Protection control encodings

-

-

-

0

Opcode fetch

-

-

-

1

Data access

-

-

0

-

User access

-

-

1

-

Privileged access

-

0

-

-

Not bufferable

-

1

-

-

Bufferable

0

-

-

-

Not cachable

1

-

-

-

Cachable