Renesas RX Series User Manual

R01UH0823EJ0100 Rev.1.00 Page 83 of 1823
Jul 31, 2019
RX23W Group 2. CPU
2.5 Endian
For the RXv2 CPU, instructions are little endian, but the treatment of data is selectable as little or big endian.
2.5.1 Switching the Endian
As arrangements of bytes, this MCU supports both big endian, where the higher-order byte (MSB) is at location 0, and
little endian, where the lower-order byte (LSB) is at location 0.
For details on the endian setting, see
section 3, Operating Modes.
Operations for access differ according to the endian setting and, depending on the instruction, whether 8-, 16- or 32-bit
access has been selected. Operations for access in the various possible cases are described in
Table 2.1 to Table 2.12.
In the tables,
LL indicates bits D7 to D0 of the general-purpose register,
LH indicates bits D15 to D8 of the general-purpose register,
HL indicates bits D23 to D16 of the general-purpose register, and
HH indicates bits D31 to D24 of the general-purpose register.
D31 to D24 D23 to D16 D15 to D8 D7 to D0
General purpose register: Rm HH HL LH LL
Table 2.1 32-Bit Read Operations when Little Endian has been Selected
Operation
Address of src
Reading a 32-bit unit
from address 0
Reading a 32-bit unit
from address 1
Reading a 32-bit unit
from address 2
Reading a 32-bit unit
from address 3
Reading a 32-bit unit
from address 4
Address 0 Transfer to LL — — — —
Address 1 Transfer to LH Transfer to LL — — —
Address 2 Transfer to HL Transfer to LH Transfer to LL — —
Address 3 Transfer to HH Transfer to HL Transfer to LH Transfer to LL —
Address 4 — Transfer to HH Transfer to HL Transfer to LH Transfer to LL
Address 5 — — Transfer to HH Transfer to HL Transfer to LH
Address 6 — — — Transfer to HH Transfer to HL
Address 7 — — — — Transfer to HH
Table 2.2 32-Bit Read Operations when Big Endian has been Selected
Operation
Address of src
Reading a 32-bit unit
from address 0
Reading a 32-bit unit
from address 1
Reading a 32-bit unit
from address 2
Reading a 32-bit unit
from address 3
Reading a 32-bit unit
from address 4
Address 0 Transfer to HH — — — —
Address 1 Transfer to HL Transfer to HH — — —
Address 2 Transfer to LH Transfer to HL Transfer to HH — —
Address 3 Transfer to LL Transfer to LH Transfer to HL Transfer to HH —
Address 4 — Transfer to LL Transfer to LH Transfer to HL Transfer to HH
Address 5 — — Transfer to LL Transfer to LH Transfer to HL
Address 6 — — — Transfer to LL Transfer to LH
Address 7 — — — — Transfer to LL

Renesas RX Series Specifications

General

Brand	Renesas
Model	RX Series
Category	Microcontrollers
Language	English