MC68HC705T16 MOTOROLA [Motorola, Inc], MC68HC705T16 Datasheet - Page 39

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

MCF - Data Transfer Complete Flag
SELTED - Addressed as Slave
When its own specific address (M-Bus Address register) matches the calling address, this bit is
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.
ALOST - Arbitration Lost
This arbitration lost bit is set by hardware when the M-bus master loses arbitration during a master
transmission mode. This bit must be cleared by software.
On entering the interrupt service routine, the M-Bus interrupt flag, MIF of M-Bus Status Register
must be cleared by software.
The interrupt service routine address is specified by the contents of memory location $FFF4 and
$FFF5. Reset disables the whole M-Bus block by clearing the M-Bus Control Register.
Refer to Section 6 for detailed description of M-Bus.
MC68HC05T16
M-Bus Status Register
1) An arbitration lost which is signified by the Arbitration Lost flag, ALOST of
2) Addressed as slave which is indicated by the master addressed as slave
3) Completed transmission or reception of one byte of data. It depends on the
1 (set)
0 (clear) –
1 (set)
0 (clear) –
M-Bus Status Register.
flag, SELTED of M-Bus Status Register.
original mode of the M-Bus interface which is determined by the
Transmit/Receive flag, XMT of M-Bus Control Register.
–
–
A byte transfer has been completed.
A byte is being transfer.
Currently addressed as a slave.
Currently not addressed.
Address bit 7
$3A
RESETS AND INTERRUPTS
MCF SELTED BBSY ALOST
bit 6
bit 5
bit 4
bit 3
SRW
bit 2
bit 1
MIF
RXACKB
bit 0
MOTOROLA
1000 0001
on reset
State
TPG
4-9
4