MC68HC705T16 MOTOROLA [Motorola, Inc], MC68HC705T16 Datasheet - Page 62

• Manufacturer Part Number: MC68HC705T16
• Description: High-density complementary metal oxide semiconductor (HCMOS) microcontroller unit
• Manufacturer: MOTOROLA [Motorola, Inc]

6
6.3.4
The MIF and ALOST bits are software clearable; while the other bits are read only.
MCF - Data Transfer Complete Flag
When MCF is set, the MIF (M-bus interrupt) bit is also set. An M-bus interrupt is generated if the
MIEN bit is set.
SELTED - Addressed as Slave Bit
This SELTED bit is set when its own specific address (M-Bus Address register) matches the
calling address. When SELTED is set, the MIF (M-bus interrupt) bit is also set. An interrupt is
generated if the MIEN bit is set. Then CPU needs to check the SRW bit and set its XMT bit
accordingly. Writing to the M-Bus Control register clears this bit.
BBSY - Bus Busy Bit
This bit indicates the status of the bus. When a START signal is detected, BBSY is set. If a STOP
signal is detected, it is cleared.
ALOST - Arbitration Lost Flag
This arbitration lost flag is set when the M-bus master loses arbitration during a master
transmission mode. When ALOST is set, the MIF (M-bus interrupt) bit is also set. This bit must be
cleared by software.
MOTOROLA
6-8
1 (set)
0 (clear) –
1 (set)
0 (clear) –
1 (set)
0 (clear) –
1 (set)
0 (clear) –
Address
$3A
M-Bus Status Register (MSR)
MCF
–
–
–
–
bit 7
A byte transfer has been completed.
A byte is being transfer.
Currently addressed as a slave.
Not currently addressed.
M-Bus busy.
M-Bus idle.
Lost arbitration in master mode.
No arbitration lost.
SELTED
bit 6
BBSY
bit 5
M-BUS SERIAL INTERFACE
ALOST
bit 4
bit 3
SRW
bit 2
bit 1
MIF
RXACKB 1000 0001
bit 0
on reset
MC68HC05T16
State
TPG