MC68HC705BD3 FREESCALE [Freescale Semiconductor, Inc], MC68HC705BD3 Datasheet - Page 40

• Manufacturer Part Number: MC68HC705BD3
• Description: High-density complementary metal oxide semiconductor (HCMOS) microcontroller unit
• Manufacturer: FREESCALE [Freescale Semiconductor, Inc]

4
Then CPU needs to check the SRW bit and set its MTX bit accordingly. Writing to the M-Bus
Control register clears this bit.
MAL - Arbitration Lost
Refer to Section 7 for detailed description of M-Bus Interface.
4.2.2.4
There are two interrupt sources, TOF and RTIF bits of Multi-Function Timer Control and Status
Register. The interrupt service routine address is specified by the contents of memory location
$3FF4 and $3FF5.
TOF - Timer Overflow
This bit is set when the 8-bit ripple counter overflows from $FF to $00; a timer overflow interrupt
will occur, if TOFIE is set. TOF is cleared by writing a “0” to the bit.
RTIF - Real Time Interrupt Flag
The clock frequency that drives the RTI circuit is E/16384, giving a maximum interrupt period of
8.19ms at a bus clock rate of 2MHz. A CPU interrupt request will be generated if RTIE is set. RTIF
is cleared by writing a “0” to the bit.
Refer to Section 5 for detailed description of Multi-Function Timer.
4-8
MFT Control and Status Register
1 (set)
0 (clear) –
1 (set)
0 (clear) –
1 (set)
0 (clear) –
Multi-Function Timer Interrupts
–
–
–
Lost arbitration in master mode.
No arbitration lost.
8-bit ripple timer overflow has occurred.
No 8-bit ripple timer overflow has occurred.
A real time interrupt has occurred.
A real time interrupt has not occurred.
Address bit 7
$0008
RESETS AND INTERRUPTS
TOF
RTIF
bit 6
TOFIE
bit 5
RTIE
bit 4
IRQN
bit 3
bit 2
bit 1
RT1
MC68HC05BD3
bit 0
RT0
0000 0011
on reset
State
TPG