mc68hc11d0cfn2 Freescale Semiconductor, Inc, mc68hc11d0cfn2 Datasheet - Page 63

• Manufacturer Part Number: mc68hc11d0cfn2
• Description: M68hc11 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

4.3.6 Highest Priority I Interrupt and Miscellaneous Register (HPRIO)
MC68HC711D3 — Rev. 2
MOTOROLA
Four bits of this register (PSEL3–PSEL0) are used to select one of the I bit related
interrupt sources and to elevate it to the highest I bit masked position of the priority
resolution circuit. In addition, four miscellaneous system control bits are included
in this register.
RBOOT — Read Bootstrap ROM
SMOD and MDA — Special Mode Select and Mode Select A
Address:
This bit can be read at any time. It can be written only in special modes
(SMOD = 1). In special bootstrap mode, it is set during reset. Reset clears it in
all other modes.
These two bits can be read at any time.These bits reflect the status of the MODA
and MODB input pins at the rising edge of reset. SMOD may be written only in
special modes. It cannot be written to a 1 after being cleared without an interim
reset. MDA may be written at any time in special modes, but only once in normal
modes. An interpretation of the values of these two bits is shown in
Reset:
Read:
Write:
1 = Bootloader ROM is enabled in the memory map at $BF00–$BFFF.
0 = Bootloader ROM is disabled and is not in the memory map.
Freescale Semiconductor, Inc.
For More Information On This Product,
MODB
RBOOT
1. The values of the RBOOT, SMOD, IRVNE, and MDA bits at reset depend on the
$003C
Bit 7
1
1
0
0
Resets, Interrupts, and Low-Power Modes
mode during initialization. Refer to
Inputs
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Table 4-3. Hardware Mode Select Summary
Figure 4-7. Highest Priority I-Bit Interrupt
MODA
SMOD
and Miscellaneous Register (HPRIO)
6
0
1
0
1
Note 1
MDA
5
Expanded multiplexed
Special bootstrap
Special test
Single chip
IRVNE
4
Mode
Table
Resets, Interrupts, and Low-Power Modes
PSEL3
4-3.
3
0
PSEL2
2
1
Latched at Reset
SMOD
0
0
1
1
PSEL1
1
0
MDA
0
1
0
1
Table
Data Sheet
Interrupts
PSEL0
Bit 0
1
4-3.
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