MC68HC908AS32A Datasheet, PDF (166/280 Pages) Freescale Semiconductor, Inc – Microcontrollers

Serial Communications Interface (SCI)
M68HC08 CPU
CPU
REGISTERS
ARITHMETIC/LOGIC
UNIT (ALU)
CONTROL AND STATUS REGISTERS
USER FLASH — 32, 256 BYTES
USER RAM — 1024 BYTES
USER EEPROM — 512 BYTES
MONITOR ROM — 256 BYTES
USER FLASH VECTOR SPACE — 52 BYTES
OSC1
OSC2
CGMXFC
CLOCK GENERATOR
MODULE
RST
SYSTEM INTEGRATION
MODULE
IRQ
IRQ MODULE
POWER-ON RESET
MODULE
V_REFH
ANALOG-TO-DIGITAL
MODULE
BREAK MODULE
LOW-VOLTAGE INHIBIT
MODULE
COMPUTER OPERATING
PROPERLY MODULE
6-CHANNEL TIMER
INTERFACE MODULE
PROGRAMMABLE INTERRUPT
TIMER MODULE
SERIAL COMMUNICATIONS
INTERFACE MODULE
SERIAL PERIPHERAL
INTERFACE MODULE
BYTE DATA LINK CONTROLLER
BDRxD
BDTxD
PTA7–PTA0
PTB7/ATD7–
PTB0/ATD0
PTC4
PTC3
PTC2/MCLK
PTC1–PTC0
PTD6/ATD14/TCLK
PTD5/ATD13
PTA4/ATD12
PTD3/ATD11–
PTD0/ATD8
PTE7/SPSCK
PTE6/MOSI
PTE5/MISO
PTE4/SS
PTE3/TCH1
PTE2/TCH0
PTE1/RxD
PTE0/TxD
PTF3/TCH5–
PTF0/TCH2
V_SS
V_DD
V_DDA
V_SSA
POWER
AV_SS/V_REFK
V_DDAREF
Figure 14-1. Block Diagram Highlighting SCI Block and Pins
14.3 Pin Name Conventions
The generic names of the SCI input/output (I/O) pins are:
• RxD (receive data)
• TxD (transmit data)
SCI I/O lines are implemented by sharing parallel I/O port pins. The full name of an SCI input or output
reflects the name of the shared port pin. Table 14-1 shows the full names and the generic names of the
SCI I/O pins. The generic pin names appear in the text of this section.
Table 14-1. Pin Name Conventions
Generic Pin Names
Full Pin Names
RxD
PTE1/SCRxD
TxD
PTE0/SCTxD
MC68HC908AS32A Data Sheet, Rev. 2.0
166
Freescale Semiconductor