Owner's manual

4-38
Ultra-High-Speed Flash
Microcontroller User’s Guide
B.7–0
Bits 7–0
B Register. This register serves as a second accumulator for certain arithmetic operations.
Bits 7–5
MPWDI
Bit 4
MPX5
Bit 3
MPX4
Bit 2
MPX3
Bit 1
MPX2
Bit 0
Reserved. Read data is 1.
Most significant priority select bit for watchdog interrupt. Most significant bit of the bit pair
MPWDI, LPWDI (EIP0.4) that designates priority level for the watchdog interrupt.
Most significant priority select bit for external interrupt 5. Most significant bit of the bit pair
MPX5, LPX5 (EIP0.3) that designates priority level for exter
nal interrupt 5.
Most significant priority select bit for external interrupt 4. Most significant bit of the bit pair
MPX4, LPX4 (EIP0.2) that designates priority level for external interrupt 4.
Most significant priority select bit for external interrupt 3. Most significant bit of the bit pair
MPX3, LPX3 (EIP0.1) that designates priority level for external interrupt 3.
Most significant priority select bit for external interrupt 2. Most significant bit of the bit pair
MPX2, LPX2 (EIP0.0) that designates priority level for external interrupt 2.
Interrupt priority level for the above sour
ces is assigned using one bit from register EIP1 (F1h) and
one bit from EIP0 (F8h). The bit from EIP1 serves as the most significant bit and the bit from EIP0
serves as the least significant bit, in forming a 2-bit binar
y number. This number represents the pri-
ority level. Higher priority interrupts, when enabled, take precedence over lower priority sources.
The power-fail warning interrupt source is assigned Priority Level 4.
R = Unrestricted read, W = Unrestricted write, -n = Value after reset
Extended Interrupt Priority 1 (EIP1)
76543210
SFR F1h — — — MPWDI MPX5 MPX4 MPX3 MPX2
R-1 R-1 R-1 RW-0 RW-0 RW-0 RW-0 RW-0
Table 4-20. Most Significant Priority Select Bit Levels
MP (EIP1.x) LP (EIP0.x) PRIORITY LEVEL
0 0 0 (natural priority)
011
102
1 1 3 (high priority)
R = Unrestricted read, W = Unrestricted write, -n = Value after reset
B Register (B)
76543210
SFR F0h B.7 B.6 B.5 B.4 B.3 B.2 B.1 B.0
RW-0 RW-0 RW-0 RW-0 RW-0 RW-0 RW-0 RW-0
Maxim Integrated