Memory-Mapped Cache Configuration (Sh7751R); Figure 4.11 Memory-Mapped Oc Data Array - Hitachi SH7751 Hardware Manual

The following two kinds of operation can be used on the OC data array:
1. OC data array read
Longword data is read into the data field from the data specified by the longword specification
bits in the address field in the OC entry corresponding to the entry set in the address field.
2. OC data array write
The longword data specified in the data field is written for the data specified by the longword
specification bits in the address field in the OC entry corresponding the entry set in the address
field. This write does not set the U bit to 1 on the address array side.
31
Address field
1 1 1 1 0 1 0 1
31
Data field
L : Longword specification bits
: Reserved bits (0 write value, undefined read value)
4.6

Memory-Mapped Cache Configuration (SH7751R)

To enable the IC and OC to be managed by software, IC contents can be read and written by a P2
area program with a MOV instruction in privileged mode. Operation is not guaranteed if access is
made from a program in another area. In this case, a branch to the P0, U0, P1, or P3 area should be
made at least 8 instructions after this MOV instruction. The OC contents can be read and written
by a P1 or P2 area program with a MOV instruction in privileged mode. Operation is not
guaranteed if access is made from a program in another area. In this case, a branch to the P0, U0,
or P3 area should be made at least 8 instructions after this MOV instruction. The IC and OC are
allocated to the P4 area in physical memory space. Only data accesses can be used on both the IC
address array and data array and the OC address array and data array, and the access size is always
longword. Instruction fetches cannot be performed in these areas. For reserved bits, a write value
of 0 should be specified, and read values are undefined. Note that the memory-mapped cache
configuration in SH7751-compatible-mode of the SH7751R is the same as that in the SH7751.
24 23

Figure 4.11 Memory-Mapped OC Data Array

14 13
Longword data
Rev. 3.0, 04/02, page 107 of 1064
5 4 2 1 0
Entry L
0