mc68hc705e5 Freescale Semiconductor, Inc, mc68hc705e5 Datasheet - Page 83

• Manufacturer Part Number: mc68hc705e5
• Description: M68hc05 Family Of Microcontrollers Mcus
• Manufacturer: Freescale Semiconductor, Inc

MC68HC705E5
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Rev. 1.0
MTX — Transmit/Receiver Mode Select Bit
TXAK — Transmit Acknowledge Enable Bit
MMUX — M-Bus Multiplexer
This bit selects the direction of master and slave transfers. When
addressed as a slave, this bit should be set by software according to
the SRW bit in the status register. In master mode, this bit should be
set according to the type of transfer required. Hence, for address
cycles this bit will always be high.
If TXAK is cleared, an acknowledge signal will be sent out to the bus
at the ninth clock bit after receiving one byte of data. When TXAK is
set, there will be no acknowledge signal response (for example,
acknowledge bit = 1).
This bit is used to enable PB7 and PB6 to be under the control of the
M-bus circuit. When set, both PB7 and PB6 become open-collector
outputs or inputs when enabled by the M-bus control. When cleared
PB7 and PB6 are under control of the port DDR logic. This bit can be
set or cleared independent of the MEN bit. Caution should be used if
PB7 and PB6 are used as general-purpose I/O.
Freescale Semiconductor, Inc.
For More Information On This Product,
1 = Transmit
0 = Receive
1 = M-bus control
0 = POR condition, port B DDR control
Motorola Bus (M Bus) Interface
Go to: www.freescale.com
Motorola Bus (M Bus) Interface
General Release Specification
M-Bus Registers