Oscillator Modes | IBM EM78P312N guide

EM78P312N

8-Bit Microcontroller

The flag (except ICIF bit) in the Interrupt Status Register (ISFR 2) is set regardless of the status of its mask bit or the execution of ENI. The RETI instruction ends the interrupt routine and enables the global interrupt (the execution of ENI).

5.16 Oscillator

5.16.1 Oscillator Modes

The EM78P312N can operate in two different oscillator modes, i.e., Crystal oscillator mode and External RC oscillator mode (ERC) oscillator mode. User can select which mode by Code Option Register. The maximum limit for operational frequencies of the crystal/resonator under different VDDs is listed below.

Table 10 Oscillator Modes Defined by SDCS and OSC

Mode

OSC

Oscillator

Single Clock

1	High frequency oscillator

0	ERC

Table 11 The Summary of Maximum Operating Speeds

Condition

VDD

Max. Fxt. (MHz)

High frequency oscillator

3.0	4.0

5.0	10.0

5.16.2 Crystal Oscillator/Ceramic Resonators (Crystal)

EM78P312N has a clock generator. i.e. fc (high frequency) which can be driven by an external clock signal through the OSCI pin.

In most applications, Pin OSCI and Pin OSCO can be connected with a crystal or ceramic resonator to generate oscillation. Table 12 provides the recommended values of C1 and C2. Since each resonator has its own attribute, user should refer to its specification for appropriate values of C1 and C2. A serial resistor Rs may be necessary for AT strip cut crystal.

50 •	Product Specification (V1.0) 10.03.2006

(This specification is subject to change without further notice)

Image 54

IBM EM78P312N Oscillator Modes, Crystal Oscillator/Ceramic Resonators Crystal, Summary of Maximum Operating Speeds

Contents

EM78P312N DOC. Version Elan Microelectronics Corporation Contents 16.2 14.116.1 16.3 General Description Bit Microcontroller Symbol Pin No Type Function Pin Description Functional Block Diagram Function Description Operating Registers Operating Registers Bit Microcontroller R0 Indirect Addressing Register R1 Time Clock /CounterR2 Program Counter & Stack Bit 7 ~ Bit 6 RBS1 ~ RBS0 R-Register page select User Memory SpaceR3 Status Register RBS1 RBS0 Bit 0 C Carry flag R4 RAM Select Register Bit 1 SIS Sleep and Idle mode selectSIS = 0 Idle mode SIS = 1 Sleep mode R5 System Control Register Bit 7 ~ Bit 0 P67 ~ P60 8-bit Port 6 I/O data register RB Timer/Counter 4 Control RegisterBit Microcontroller R6 Port 6 I/O Data Register R7 Port 7 I/O Data Register TC4CK2 TC4CK1 TC4CK0 RC Timer 4 Data BufferClock Source Resolution Max. Time Fosc=8M Bit Microcontroller RE Interrupt Status Flag Register RFInterrupt Status Flag Register Bank 1 R7 TC3DB Timer 3 Data Buffer B Bank 1 R5 TC3CR Timer/Counter 3 Control RegisterTC3M = 1 Capture mode Bank 1 R6 TC3DA Timer 3 Data Buffer a Bit 7 TC3CAP Software capture control TC2S = 0 Stop and counter clear Bank 1 R9 TC2DH Timer 2 Data Buffer High ByteBank 1 RA TC2DL Timer 2 Data Buffer Low Byte Bank 1 RB Adcr AD Control Register Bank 1 RC Adic AD Input Pin Control Bit 7 ~ Bit 0 ADE7 ~ ADE0 AD input pin enable controlBit 5~ Bit 4 ADCK1 ~ ADCK0 AD Conversion Time Select Bank 1 RD Addh AD High 8-bit Data Buffer Bank 2 R5 URC1 Uart Control Register TEN = 0 Disable TEN = 1 EnableBit Microcontroller Bank 1 RE Tbktc TBT/Keytone Control Bit BRATE2 BRATE1 BRATE0 Bank 2 R7 URS Uart Status RegisterBit 7 URRD8 Receiving data Bit TC2CK1 TC2CK0 Even = 0 Odd parity Even = 1 Even parity Bit 5 PRE Enable parity additionBit 6 Even Select parity check Bank 2 R9 Urtd Uart Transmit Data Buffer EDS = 0 Rising edge EDS = 1 Falling edge Bit 5 ~ Bit 3 BRS0 ~ BRS2 SPI Clock Source SelectBit 2 EDS Data shift out edge select Bit 0 WBE Write buffer empty flag. Read only Bank 3 RB PLC1 Pull Low Control Register PHE6x = 1 Disable P6x pull highTransfer Mode SPID7 SPID6 SPID5 SPID4 SPID3 SPID2 SPID1 SPID0 Special Purpose Registers INT1ES = 0 Rising edge INT1ES = 1 Falling edge IOC6 ~ IOC9 − I/O Port Control RegisterIntcr − INT Control Register Address 0Bh TC2ES = 0 Rising edge TC2ES = 1 Falling edge External Interrupt Adoscr − AD Offset Control Register Address 0ChCali Sign IMR2 − Interrupt Mask Register 2 Address 0Fh Uerrie Urie Utie Tbie EXIE1 TCIE0 Mode Switching Control CPU Operation ModeRegisters for CPU Operation Mode Operation Mode AD Converter Sleep Mode Idle ModeWake-up Signal R5 SIS = 1+SLEP R5 SIS= 0 + Slep Instruction Wake-up Methods Sampling Time Operation Mode Max. Frequency Max. Conversion Rate per BitADC Data Register Conversion Time Time Base Timer and Keytone Generator Address Name Bit MUX Uart Universal Asynchronous Receiver/Transmitter Registers for Uart CircuitName Bit Uart Mode Transmitting Receiving Baud Rate Generator SPI Serial Peripheral Interface Registers for the SPI CircuitRbank Address Name Bit Bit Transmit Mode Shift Direction and Sample PhaseTransfer Mode Serial Clock Bit Microcontroller Bit Receive Mode Bit Transmit/Receive ModeSCK pin Spis Multiple Device Connect /SS Timer/Counter Registers for Timer/Counter 2 Circuit Timer Mode Counter ModeWindow Mode Registers for Timer/Counter 3 Circuit 21 Window Mode Timing Chart Capture Mode 22 Configuration of Timer/Counter3 Registers for Timer 4 Circuit TCIF4 PDO Mode TCR4 Up-counter PWM Mode12 TCC/WDT & Prescaler TC4 Interrupt Reset and Wake-up Reset13 I/O Ports Wake-up from Sleep Mode Wake-up from Idle Mode Address Name Reset Type Bit Summary of the Initialized Values for Registers Bit Microcontroller Register Bank SCR Addres URTD8 Bit Microcontroller General Purpose Registers Reset TypeStatus of RST, T, and P of the Status Register Events that may affect the T and P Status 28 Controller Reset Block Diagram Interrupt Crystal Oscillator/Ceramic Resonators Crystal OscillatorOscillator Modes Summary of Maximum Operating Speeds Oscillator Type Frequency Mode Frequency C1 pF C2 pF 740 EM78P312N 809N External RC Oscillator Mode OS CI Code Option Register Word Enwdtb = 0 Enable Enwdtb = 1 DisableCode Option Register Bit 12 ~ 9 Not used Customer ID Register Power-on ConsiderationsExternal Power-on Reset Circuit OSC = 0 RC type OSC = 1 Crystal type EM78P312N Residue-Voltage ProtectionVdd EM78P809N Instruction Set Binary Instruction Hex Mnemonic Operation Status Binary Instruction Hex Mnemonic Operation Status Affected DEC Recommended Operating Conditions Symbol Parameter Condition Min Typ Max UnitAbsolute Maximum Ratings Vss = DC Electrical Characteristics Ta= 25 C, VDD= 5.0V ± 5%, VSS= Ta= 25 C, VDD= 3.0V ± 5%, VSS= Varef AC Electrical Characteristic Symbol Parameter Conditions Min Typ Max UnitTa=- 40C ~ 85 C, VDD=5V ± 5%, VSS=0V Timing Diagram AC Test Input/Output Waveform Pin Count Package Size OTP MCUPackage Type EM78P311SxY