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Section 7 Interrupt Controller
Page 202 of 2108 R01UH0134EJ0400 Rev. 4.00
Sep 24, 2014
SH7262 Group, SH7264 Group
7.8.1 Banked Register and Input/Output of Banks
(1) Banked Register
The contents of the general registers (R0 to R14), global base register (GBR), multiply and
accumulate registers (MACH and MACL), and procedure register (PR), and the vector table
address offset are banked.
(2) Input/Output of Banks
This LSI has fifteen register banks, bank 0 to bank 14. Register banks are stacked in first-in last-
out (FILO) sequence. Saving takes place in order, beginning from bank 0, and restoration takes
place in the reverse order, beginning from the last bank saved to.
7.8.2 Bank Save and Restore Operations
(1) Saving to Bank
Figure 7.11 shows register bank save operations. The following operations are performed when an
interrupt for which usage of register banks is allowed is accepted by the CPU:
a. Assume that the bank number bit value in the bank number register (IBNR), BN, is i before the
interrupt is generated.
b. The contents of registers R0 to R14, GBR, MACH, MACL, and PR, and the interrupt vector
table address offset (VTO) of the accepted interrupt are saved in the bank indicated by BN,
bank i.
c. The BN value is incremented by 1.
Bank 0
Register banks Registers
Bank 1
:
:
:
:
Bank i
Bank i + 1
Bank 14
+1
(a)
(c)
(b)
BN
GBR
MACH
MACL
PR
VTO
R0 to R14
Figure 7.11 Bank Save Operations