sc9s08mz16 Freescale Semiconductor, Inc, sc9s08mz16 Datasheet - Page 227

• Manufacturer Part Number: sc9s08mz16
• Description: Hcs08 Microcontrollers
• Manufacturer: Freescale Semiconductor, Inc

Figure 12-3
asynchronous to the target MCU, there is a 0-to-1 cycle delay from the host-generated falling edge on
BKGD to the perceived start of the bit time in the target MCU. The host holds the BKGD pin low long
enough for the target to recognize it (at least two target BDC cycles). The host must release the low drive
before the target MCU drives a brief active-high speedup pulse seven cycles after the perceived start of the
bit time. The host should sample the bit level about 10 cycles after it started the bit time.
Freescale Semiconductor
SYNCHRONIZATION
PERCEIVED START
(TARGET MCU)
BDC CLOCK
UNCERTAINTY
TRANSMIT 1
TRANSMIT 0
OF BIT TIME
HOST
HOST
shows the host receiving a logic 1 from the target HCS08 MCU. Because the host is
Figure 12-2. BDC Host-to-Target Serial Bit Timing
SC9S08MZ16 MCU Data Sheet, Rev. 1
TARGET SENSES BIT LEVEL
10 CYCLES
EARLIEST START
OF NEXT BIT
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