HD6433044 Hitachi Semiconductor, HD6433044 Datasheet - Page 529

• Manufacturer Part Number: HD6433044
• Description: (HD64 Series) Hitachi Single-Chip Microcomputer
• Manufacturer: Hitachi Semiconductor

14.4 Usage Notes
When using the SCI as a smart card interface, note the following points.
Receive Data Sampling Timing in Smart Card Mode and Receive Margin: In smart card
mode the SCI operates on a base clock with 372 times the bit rate frequency. In receiving, the SCI
synchronizes internally with the fall of the start bit, which it samples on the base clock. Receive
data is latched at the rising edge of the 186th base clock pulse. See figure 14-10.
Internal
base clock
Receive data
(RxD)
Synchronization
sampling timing
Data sampling
timing
Figure 14-10 Receive Data Sampling Timing in Smart Card Mode
0
186 clocks
185
372 clocks
Start
bit
371
519
0
D0
185
371
0
D1