MB91155 datasheet(22/105 Pages) FUJITSU

22 / 105 page

MB91F155A/MB91155/MB91154

• Condition Code Register (CCR)

• System condition Code Register (SCR)

• Interrupt Level Mask register (ILM)

S flag

: Designates the stack pointer for use as R15.

I flag

: Controls enabling and disabling of user interrupt requests.

N flag

: Indicates the sign when arithmetic operation results are considered to be an integer represented

by 2’s complement.

Z flag

: Indicates if arithmetic results were “0.”

V flag

: Considers the operand used for an arithmetic operation to be an integer represented by 2’s com-

plement and indicates if the operation resulted in an overflow.

C flag

: Indicates whether or not an arithmetic operation resulted in a carry or a borrow from the most sig-

nificant bit.

T flag

: Designates whether or not to enable step trace trap.

ILM4 to ILM0

: Holds an interrupt level mask value to be used for level masking.

An interrupt request is accepted only if the corresponding interrupt level among interrupt

requests input to the CPU is higher than the value indicated by the ILM register.

ILM4

ILM3

ILM2

ILM1

ILM0

Interrupt level

High-Low

00000

Higher

01000

Lower

MB91155 Datasheet(PDF) 22 Page - fujitsu semiconductor