HD404669 Datasheet, PDF (77/142 Pages) Hitachi Semiconductor – Low-Voltage AS Microcomputers with On-Chip DTMF Generation Circuit

Serial Interface
Serial Interface Overview
Function
• 8-bit serial data transmission/reception
Features
• Multiple transmit clock sources
 External clock
 Internal prescaler output clock
 System clock
• High/low control in idle states
Configuration
• Serial data register 1 (SR1L: $006, SR1U: $007)
• Serial mode register 1 A (SM1A: $005)
• Serial mode register 1 B (SM1B: $028)
• Port mode register A (PMRA: $004)
• Miscellaneous register (MIS: $00C)
• Octal counter (OC1)
• Selector
The block diagram of the serial interface is shown in figure 58.
HD404669 Series
77