MC68HC11E0 Motorola, MC68HC11E0 Datasheet - Page 35

• Manufacturer Part Number: MC68HC11E0
• Description: (MC68HC711E Series) M68HC11E Series Programming Reference Guide
• Manufacturer: Motorola

Highest Priority I Bit Interrupt and Miscellaneous (HPRIO)
MOTOROLA
Reset:
1. The values of the RBOOT, SMOD, and MDA reset bits depend on the mode selected at the
Address:
Special test:
RBOOT — Read Bootstrap ROM
SMOD and MDA — Special Mode Select and Mode Select A
IRVNE — Internal Read Visibility/Not E (IRV in MC68HC811E2)
Single chip:
Expanded:
Bootstrap:
RESET pin rising edge.
M68HC11E Series Programming Reference Guide
Valid only when SMOD is set to 1 (bootstrap or special test mode). Can only
be written in special modes.
The initial value of SMOD is in the inverse of the logic level present on the
MODB pin at the rising edge of reset. The initial value of MDA equals the
logic level present on the MODA pin at the rising edge of reset. These two
bits can be read at any time. They can be written anytime in special modes.
MDA can only be written once in normal modes. SMOD cannot be set once
it has been cleared. Refer to the following table.
IRVNE can be written once in any mode. In expanded modes, IRVNE
determines whether IRV is on or off. In special test mode, IRVNE is reset
to 1. For the MC68HC811E2, this bit controls only internal read visibility
function and has no meaning or effect in single-chip modes.
In single-chip modes this bit determines whether the E clock drives out from
the chip.
Read:
Write:
Single chip
Expanded
Bootstrap
Special test
0 = Bootloader ROM disabled and not in map
1 = Bootloader ROM enabled and in map at $BE00–$BFFF
0 = No internal read visibility on external bus
1 = Data from internal reads is driven out the external data bus
0 = E is driven out from the chip.
1 = E pin is driven low. Refer to the following table.
MODB
Mode
$103C
1
1
0
0
RBOOT
Bit 7
0
0
1
0
Inputs
(1)
IRVNE Out
of Reset
SMOD
MODA
0
0
0
1
6
0
0
1
1
0
1
0
1
(1)
MDA
E Clock Out
5
0
1
0
1
of Reset
(1)
On
On
On
On
Special test
Single chip
Expanded
Bootstrap
Mode
IRVNE
4
0
0
0
1
of Reset
IRV Out
Off
Off
Off
On
PSEL3
3
0
0
0
0
Affects Only
SMOD
PSEL2
IRVNE
M68HC11E Series Registers
Latched at Reset
0
0
1
1
IRV
IRV
2
1
1
1
1
E
E
M68HC11ERG/AD
PSEL1
1
1
1
1
1
IRVNE Can
Be Written
MDA
Once
Once
Once
Once
0
1
0
1
PSEL0
Bit 0
0
0
0
0
35