EM78P451 OTP ROM 1. GENERAL DESCRIPTION The EM78P451 is an 8-bit microprocessor designed and developed with low-power, high speed CMOS technology. Its operational kernel is implemented with RISC-like architecture and is available in the mask ROM version. The one time programmable (OTP) version is flexible, both in mass production or engineering test stages. OTP provide users with unlimited volume with favorable price opportunities. This device is equipped with the Serial Peripheral Interface (SPI) function and an easy-implemented RS-232. The EM78P451 is very suitable for wired communication. Only 58 easy-to-learn instructions are needed and user’s program can be emulated with EMC In-Circuit Emulator (ICE). This specification is subject to change without prior notice. 1 2002/03/01 EM78P451 OTP ROM 2. FEATURES • Operating voltage range: 2.3V~5.5V. • Operating temperature range: 0°C~70°C. • Operating frequency rang (base on 2 clocks ): * Crystal mode: DC~20MHz at 5V, DC~8MHz at 3V, DC~4MHz at 2.3V. * RC mode: DC~4MHz at 5V, DC~4MHz at 3V, DC~4MHz at 2.3V. • Low power consumption: * Less then 3 mA at 5V/4MHz * Typically 10 µA during sleep mode • Serial Peripheral Interface (SPI) available. • 4K × 13 bits on chip ROM (EM78P451). • 11 special function registers. • 140× 8 bits on chip general-purposed registers. • 5 bi-directional I/O ports (35 I/O pins). • 3 LED direct sinking pins with internal serial resistors. • Built-in RC oscillator with external serial resistor, ±10% variation. • Built-in power-on reset. • 5 stacks for subroutine nesting. • 8-bit real time clock/counter (TCC) with overflow interrupt. • Two machine clocks or four machine clocks per instruction cycle. • Power down mode. • Programmable wake up from sleep circuit on I/O ports. • Programmable free running on-chip watchdog timer. • 12 wake-up pins. • 2 open-drain pins. • 2 R-option pins. • 32 programmable pull-high input pins. • Packages: * 40 pin DIP 600mil : EM78P451P. * 44 pin QFP : EM78P451AQ. This specification is subject to change without prior notice. 2 2002/03/01 EM78P451 OTP ROM • Four types of interrupts. * External interrupt (/INT). * SPI transmission completed interrupt. * TCC overflow interrupt. * Timer1 comparator match interrupt. This specification is subject to change without prior notice. 3 2002/03/01 EM78P451 OTP ROM 3. PIN ASSIGNMENT 36 P 7 1 35 P 7 2 34 P 6 7 P90 1 33 P71 33 P 6 6 P91 32 31 P72 32 2 3 P 6 5 4 30 P66 5 29 P65 28 P64 P63 7 8 27 26 P52 9 25 P61 P53 P54 10 24 P60 11 23 P87 P51 13 28 P 6 1 P 5 3 14 27 P 6 0 P 5 4 15 26 P 8 7 P 5 5 16 25 P 8 6 P 5 6 17 24 P 8 5 P 5 7 18 23 P 8 4 P 8 0 19 22 P 8 3 P 8 1 20 21 P 8 2 37 P50 P 6 2 P 5 2 EM78P451AQ SS/P95 P62 P 8 6 22 29 P 6 3 P67 6 P 8 5 21 12 30 P 6 4 P 8 4 20 P 5 1 11 31 P 8 3 19 P 5 0 10 P 8 2 18 S S / P 9 5 SDI/P92 SDO/P93 SCK/P94 17 9 NC S C K / P 9 4 P 8 1 16 8 P 8 0 15 S D O / P 9 3 P 5 7 14 7 P 5 5 12 6 P 5 6 13 P 9 1 S D I / P 9 2 P 7 0 34 P 7 0 5 35 N C P 9 0 NC 37 36 N C 4 38 V D D V D D C L K 39 R - O S C I 38 40 O S C O 3 41 V S S R - O S C I D A T A 43 D A T A O S C O 39 42 I N T 40 2 44 C L K 1 I N T E M 7 8 P 4 5 1 P / W M V S S Fig. 1 Pin Assignment Table 1 Pin description Symbol Pin No. Type R-OSCI 39 I OSCO 40 O 5~10 I/O P80~P87 19~26 I/O P70~P72 37~35 I/O CLK 4 I/O DATA 3 I/O P90~P95 P60~P67 27~34 I/O P50~P57 11~18 I/O VDD VSS /INT 38 1 2 I Function Description * In XTAL mode: Crystal input; In internal C, external R mode: 56Kohm±5% pull high for 1.8432MHz. * In XTAL mode: Crystal output; In RC mode: Instruction clock output. * General bi-directional I/O port. All of its pins can be pulled-high by software. P90 and P91 are pin-change wake up pins. * General bi-directional I/O port. All of its pins can be pulled-high by software. P80 and P81 are also used as the R-option pins. * LED direct-driving pin with internal serial resistor used as output and is software defined. * By connecting P74 and P76 together. * P74 can be pulled-high by software and it is also a pin-change wake up pin. * P76 can be defined as an open-drain output. * By connecting P75 and P77 together. * P75 can be pulled-high by software and it is also a pin-change wake up pin. * P77 can be defined as an open-drain output. * General bi-directional port. All of its pins can be pulled-high by software, and pin-change wake up pins. * General bi-directional I/O port. All of its pins can be pulled-high individually by software. * Power supply pin. * Ground pin. * An interrupt schmitt-triggered pin. This specification is subject to change without prior notice. 4 2002/03/01 EM78P451 OTP ROM SDI SDO SCK /SS 7 8 9 10 I/O I/O I/O I/O * The function of interrupt triggers at the falling edge. * Users can enable it by software. The internal pull-up resistor is around 50K ohms. * Serial data in for SPI * Serial data out for SPI. * Serial clock for SPI. * /Slave select for SPI. This specification is subject to change without prior notice. 5 2002/03/01 EM78P451 OTP ROM 4. FUNCTION DESCRIPTION WDT Timer WDT Time-out P C STACK 1 STACK 2 Prescaler STACK 3 Oscillator/ /INT Timming STACK 4 ROM STACK 5 Control Interrupt Instruction Control Register R1(TCC) ALU Instruction Sleep RAM Decoder & Wake Up Control R3 ACC TMR1 R4 DATA & CONTROL BUS IOC5 IOC6 IOC7 R5 R6 R7 P P PP P P PP 5 5 55 5 5 55 0 1 23 4 5 67 P P P PP P P P 6 6 6 66 6 6 6 0 1 2 34 5 6 7 P 7 0 P 7 1 IOC9 IOC8 R8 P 7 2 P P PP P PP P 8 8 88 8 88 8 0 1 23 4 56 7 R9 SPI ENGIN P P P P 9 9 9 9 0 1 2 3 / / S S D D P P 9 5 4 5 / / S / C S I O K S Fig. 2 Functional Block Diagram 4.1 Operational Registers 1. R0 (Indirect Address Register) R0 is not a physically implemented register. It is used as an indirect addressing pointer. Any instruction using R0 as register actually accesses data pointed by the RAM Select Register (R4). 2. R1 (TCC) • Increased by the instruction cycle clock. • Written and read by program as any other register. 3. R2 (Program Counter) & Stack • R2 and the hardware stacks are 12 bits wide. • The structure is depicted in Fig. 3. This specification is subject to change without prior notice. 6 2002/03/01 EM78P451 OTP ROM • Generates 4K × 13 on-chip ROM addresses to the relative programming instruction codes. One program page is 1024 words long. • All the R2 bits are set to "1"s as a RESET condition occurs. • "JMP" instruction allows direct loading of the lower 10 program counter bits. Thus, "JMP" allows jump to any location on one page. • "CALL" instruction loads the lower 10 bits of the PC, and then PC+1 is pushed into the stack. Thus, the subroutine entry address can be located anywhere within a page • "RET" ("RETL k", "RETI") instruction loads the program counter with the contents at the top of stack. • "MOV R2, A" allows the loading of an address from the "A" register to the lower 8 bits of PC, and the ninth and tenth bits (A8~A9) of PC are cleared. • "ADD R2, A" allows a relative address be added to the current PC, and the ninth and tenth bits of PC are cleared. • Any instruction that is written to R2 (e.g. "ADD R2, A", "MOV R2, A", "BC R2,6",⋅⋅⋅⋅⋅) (except "TBL") will cause the ninth and tenth bits (A8~A9) of PC to be cleared. Thus, the computed jump is limited to the first 256 locations of any program page. • "TBL" allows a relative address be added to the current PC (R2+A→R2), and contents of the ninth and tenth bits (A8~A9) of PC are not changed. Thus, the computed jump can be on the second (or third, 4th) 256 locations on one program page. • In case of EM78P451, the most significant bits (A10~A11) will be loaded with the contents of bits PS0~PS1 in the status register (R3) upon the execution of a "JMP", "CALL", or any other instructions which writes to R2. • All instructions are single instruction cycle (fclk/2 or fclk/4) except for the instruction that would change the contents R2. Such instruction will need one more instruction cycle. CALL PC A11A10 A9A8 A7 ~ A0 RET RETL RETI 00 400 7FF 10 Stack 3 Stack 4 Page 0 0 0 1 : H a r e w a r e i nt e r r u p t l o c a t i o n 002:Software interrupt (INT instruction) location Page 1 FFF:Reset location 800 BFF 11 Stack 2 Stack 5 000 3FF 01 Stack 1 Page 2 C00 FFF Page 3 Fig. 3 Program Counter Organization This specification is subject to change without prior notice. 7 2002/03/01 EM78P451 OTP ROM 4. R3 (Status Register) 7 GP 6 PS1 5 PS0 4 T 3 P 2 Z 1 DC 0 C • Bit 0 (C) Carry flag • Bit 1 (DC) Auxiliary carry flag • Bit 2 (Z) Zero flag. Set to "1" if the result of an arithmetic or logic operation is zero. • Bit 3 (P) Power down bit. Set to 1 during power on or by a "WDTC" command and reset to 0 by a "SLEP" command. • Bit 4 (T) Time-out bit. Set to 1 with the "SLEP" and the "WDTC" commands, or during power up and reset to 0 with WDT timeout. • Bits 5 (PS0) ~ 6 (PS1) Page select bits. PS0~PS1 are used to pre-select a program memory page. When executing a "JMP", "CALL", or other instructions which causes the program counter to be changed (e.g. MOV R2, A), PS0~PS1 are loaded into the 11th and 12th bits of the program counter where it selects selecting one of the available program memory pages. Note that RET (RETL, RETI) instruction does not change the PS0~PS1 bits. That is, the return will always be to the page from where the subroutine was called, regardless of the current setting of PS0~PS1 bits. PS1 bit is not used (read as "0") and cannot be modified in EM78P451. PS1 0 0 1 1 PS0 0 1 0 1 Program memory page [Address] Page 0 [000-3FF] Page 1 [400-7FF] Page 2 [800-BFF] Page 3 [C00-FFF] • Bit 7 (GP) General read/write bit. 5. R4 (RAM Select Register) • Bits 0~5 are used to select the registers (address: 00~3F) in the indirect addressing mode. • Bits 6~7 determine which bank is activated among the 4 banks. • If no indirect addressing is used, the RSR is used as an 8-bit general-purposed read/writer register. • See the configuration of the data memory in Fig. 4. 6. R5~R8 (Port 5 ~ Port8) • Four general 8 bits I/O registers • Both P74 and P76 read or write data from the DATA pin, while both P75 and P77 read or write data from the CLK pin. 7. R9 (Port9) • A general 6-bit I/O register. The values of the two most significant bits are read as "0". This specification is subject to change without prior notice. 8 2002/03/01 EM78P451 OTP ROM 00 R0 01 R1 (TCC) 02 R2 (PC) STACK 0 03 R3 (Status) STACK 1 04 R4 (RSR) STACK 2 05 R5 (Port 5) STACK 3 IOC5 06 R6 (Port 6) STACK 4 IOC6 07 R7 (Port 7) IOC7 08 R8 (Port 8) IOC8 09 R9 (Port 9) IOC9 0A RA 0B RB 0C RC IOCC 0D RD IOCD 0E RE IOCE 0F RF IOCF 10 11 16x8 Common Register 1E 1F 00 01 10 11 20 21 31x8 Bank Register 31x8 Bank Register 31x8 Bank Register 31x8 Bank Register (Bank 0) (Bank 1) (Bank 2) (Bank 3) 3E 3F R3F Fig. 4 Data memory configuration This specification is subject to change without prior notice. 9 2002/03/01 EM78P451 OTP ROM 8. RA (SPIRB: SPI Read Buffer) Address Name 0X0A SPIRB/RA Bit 7 SRB7 Bit 6 SRB6 Bit 5 SRB5 Bit 4 SRB4 Bit 3 SRB3 Bit 2 SRB2 Bit 1 SRB1 • SRB7~SRB0 are the 8-bit data when complete transmission by SPI. 9. RB (SPIWB: SPI Write Buffer) Address Name 0x0B SPIWB/RB Bit 7 SWB7 Bit 6 SWB6 Bit 5 SWB5 Bit 4 SWB4 Bit 3 SWB3 Bit 2 SWB2 Bit 1 SWB1 Bit 0 SWB0 Bit 1 RBFIF Bit 0 RBF • SWB7~SWB0 are the 8-bit data that are waiting for transmission by SPI. 10. RC (SPIS: SPI Status Segister) Address 0x0C Name SPIS/RC Bit 7 -- Bit 6 -- Bit 5 -- Bit 4 TM1IF Bit 3 OD3 Bit 2 OD4 • TM1IF (bit 4): 1 = In timer1 mode, receiving completed, and an interrupt occurs if enabled. 0 = In timer1 mode, receiving not completed yet, and an interrupt does not occur. • OD3 (bit 3): Open-Drain Control bit 1 = Open-drain enable for SDO, 0 = Open-drain disable for SDO. • OD4 (bit 2): Open-Drain Control bit 1 = Open-drain enable for SCK, 0 = Open-drain disable for SCK. • RBFIF (bit 1):Read Buffer Full Interrupt Flag 1 = Receiving completed, SPIRB is fully exchanged, and an interrupt occurs if enabled. 0 = Receiving not completed yet; and SPIRB has not fully exchanged. • RBF (bit 0): Read Buffer Full flag 1 = Receiving completed; SPIRB is fully exchanged. 0 = Receiving not completed yet, and SPIRB has not fully exchanged. 11. RD (SPIC: SPI Control Register) Address 0x0D Name SPIC/RD Bit 7 CES Bit 6 SPIE Bit 5 SRO Bit 4 SSE Bit 3 - Bit 2 SBRS2 Bit 1 Bit 0 SBRS1 SBRS0 • CES (bit 7): Clock Edge Select bit 1 = Data shifts out on falling edge, and shifts in on rising edge. Data is on hold during the high level. 0 = Data shifts out on rising edge, and shifts in on falling edge. Data is on hold during the low level. • SPIE (bit 6): SPI Enable bit 1= Enable SPI mode This specification is subject to change without prior notice. 10 2002/03/01 EM78P451 OTP ROM 0= Disable SPI mode • SRO (bit 5): SPI Read Overflow bit 1 = A new data is received while the previous data is still being held in the SPIB register. In this situation, the data in SPIS register will be destroyed. To avoid setting this bit, users had better read SPIRB register even if only the transmission is implemented. 0 = No overflow. <Note>: This can only occur in slave mode. • SSE (bit 4): SPI Shift Enable bit 1 = Start to shift, and keep on 1 while the current byte is still being transmitted. 0 = Reset as soon as the shifting is complete, and the next byte is ready to shift. <Note>: This bit will reset to 0 at every one-byte transmission by the hardware • SBRS (bit 2~bit 0): SPI Baud Rate Select bits SPI baud rate table is illustrated in SPI section in later pages. 12. RE (TMR1: Timer1 register) Address 0X0E Name Bit 7 TMR1/RE TMR17 Bit 6 TMR16 Bit 5 TMR15 Bit 4 TMR14 Bit 3 TMR13 Bit 2 TMR12 Bit 1 Bit 0 TMR11 TMR10 • TMR17~TMR10 is bit set of timer1 register and it increases until the value matches PWP and then, it resets to 0. 13. RF (PWP: Pulse width preset register) Address Name 0x0F PWP/RF Bit 7 PWP7 Bit 6 PWP6 Bit 5 PWP5 Bit 4 PWP4 Bit 3 PWP3 Bit 2 PWP2 Bit 1 PWP1 Bit 0 PWP0 • PWP7~PWP0 is bit set of pulse width preset in advance for the desired width of baud clock. 14. R20~R3E (General Purpose Register) • RA~R1F, and R20~R3E (including Banks 0~3) are general-purpose registers. 15. R3F (Interrupt Status Register) Address Name 0x3F ISR/R3F Bit 7 - Bit 6 - Bit 5 - Bit 4 - Bit 3 TM1IF Bit 2 SPIIF Bit 1 EXIF Bit 0 TCIF • Bit 0 (TCIF) the flag of the TCC overflow interrupt. Set as TCC overflow; flag cleared by software. • Bit 1 (EXIF) External interrupt flag. Set by falling edge on /INT pin, flag cleared by software • Bit 2 (SPIIF) SPI interrupt flag. Set by data transmission complete, flag cleared by software. • Bit 3 (TM1IF) Timer1 interrupt flag. Set by the comparator at Timer1 application, flag cleared by software. • Bits 2~7 are not used and read as “0”. This specification is subject to change without prior notice. 11 2002/03/01 EM78P451 OTP ROM • "1" means interrupt request, "0" means non-interrupt. • R3F can be cleared by instruction, but cannot be set by instruction. • IOCF is the interrupt mask register. • Note that to read R3F will result to "logic AND" of R3F and IOCF. 4.2 Special Purpose Registers 1. A (Accumulator) • Internal data transfer, or instruction operand holding. • A non-addressable register. 2. CONT (Control Register) 7 /PHEN 6 /INT 5 - 4 - 3 PAB 2 PSR2 1 PSR1 0 PSR0 • Bit 7 (/PHEN) I/O pin pull-high enable flag. 0: For P60~P67, P74~P75 and P90~P95, the pull-high function is enabled. 1: The pull-high function is disabled. • Bit 6 (INT) An interrupt enable flag cannot be written by the CONTW instruction. 0: interrupt masked by the DISI instruction. 1: interrupt enabled by the ENI or RETI instruction. • Bit4, 5 Not used, and to be read as “0”. • Bit 3 (PAB) Prescaler assignment bit. 0: TCC 1: WDT • Bit 0 (PSR0) ~ Bit 2 (PSR2) TCC/WDT prescaler bits. PSR2 0 0 0 0 1 1 1 1 PSR1 0 0 1 1 0 0 1 1 PSR0 0 1 0 1 0 1 0 1 TCC Rate 1:2 1:4 1:8 1:16 1:32 1:64 1:128 1:256 WDT Rate 1:1 1:2 1:4 1:8 1:16 1:32 1:64 1:128 • Bits 0~3, and 7 of the CONT register are readable and writable. 3. IOC5 ~ IOC9 (I/O Port Control Register) • "1" put the relative I/O pin into high impedance, while "0" put the relative I/O pin as output. This specification is subject to change without prior notice. 12 2002/03/01 EM78P451 OTP ROM • Both P74 and P76 should not be defined as output pins at the same time. This also applies to both P75 and P77. • Only the lower 6 bits of the IOC9 register are used. 4. IOCC (T1CON: Timer1 control register) Address Name 0x0C T1CON/IOCC Bit 7 0 Bit 6 0 Bit 5 0 Bit 4 0 Bit 3 0 Bit 2 TM1E Bit 1 TM1P1 Bit 0 TM1P0 • TM1E (bit2): Timer1 Function Enable bit 1 = Enable timer1 function. 0 = Disable timer1 function as default. • TM1P (bit1~bit0): Timer1 Prescaler bit Timer1 prescaler table for FOSC will be illustrated in the Section on Timer1 in later pages. 5. IOCD (Pull-high Control Register) 7 S7 6 - 5 - 4 - 3 /PU9 2 /PU8 1 /PU6 0 /PU5 • The default values of /PU5, /PU6, /PU8, and /PU9 are one, which means the pull-high function is disabled. • /PU6 and /PU9 are “AND” gating with /PHEN, that is, when each one is written as “0” pull high is enabled. • S7 defines the driving ability of the P70-P72. 0: Normal output. 1: Enhance the driving ability of LED. 6. IOCE (WDT Control Register) 7 - 6 ODE 5 WDTE 4 SLPC 3 ROC 2 - 1 - 0 /WUE • Bit 0 (/WUE) Control bit used to enable the wake-up function of P60~P67, P74~P75, and P90~P91. 0: Enable the wake-up function. 1: Disable the wake-up function. The /WUE bit can be read and written. • Bit 3 (ROC) ROC is used for the R-option. Setting ROC to "1" will enable the status of R-option pins (P80, P81) to be read by the controller. Clearing ROC will disable the R-option function. Otherwise, the R-option function is introduced. Users must connect the P81 pin or/and P80 pin to VSS by a 560KΩ external resistor (Rex). If Rex is connected/disconnected with VDD, the status of P80 (P81) will be read as "0"/"1" (refer to Fig. 7(b)). The ROC bit can be read and written. This specification is subject to change without prior notice. 13 2002/03/01 EM78P451 OTP ROM • Bit 4 (SLPC) This bit is set by hardware at the falling edge of wake-up signal and is cleared in software. SLPC is used to control the oscillator operation. The oscillator is disabled (oscillator is stopped, and the controller enters the SLEEP2 mode) on the high-to-low transition and is enabled (the controller is awakened from SLEEP2 mode) on low-to-high transition. In order to ensure the stable output of the oscillator, once the oscillator is enabled again, there is a delay for approximately 18 ms (oscillator start-up timer (OST)) before the next program instruction is executed. The OST is always activated by wake-up from sleep mode whether the Code Option bit ENWDT is "0" or not. After waking up, the WDT is enabled if Code Option ENWDT is "1". The block diagram of SLEEP2 mode and wake-up caused by input triggered is depicted in Fig. 5. The SLPC bit can be read and written. • Bit 5 (WDTE) Control bit used to enable Watchdog timer. The WDTE bit can be used only if ENWDT, the CODE Option bit, is "1". If the ENWDT bit is "1", then WDT can be disabled/enabled by the WDTE bit. 0: Disable WDT. 1: Enable WDT. The WDTE bit is not used if ENWDT, the CODE Option bit ENWDT, is "0". That is, if the ENWDT bit is "0", WDT is always disabled no matter what the WDTE bit is. The WDTE bit can be read and written. • Bit 6 (ODE) Open-drain control bit. 0: Both P76 and P77 are normally I/O pins. 1: Both P76 and P77 pins have the open-drain function inside. The ODE bit can be read and written. • Bits 1~2, and 7 Not used. 7. IOCF (Interrupt Mask Register) 7 - 6 - 5 - 4 - 3 TM1IE 2 SPIIE 1 EXIE 0 TCIE • Bit 0 (TCIE) TCIF interrupt enable bit. 0: disable TCIF interrupt 1: enable TCIF interrupt • Bit 1 (EXIE) EXIF interrupt enable bit. 0: disable EXIF interrupt 1: enable EXIF interrupt • Bit 2 (SPIIE) SPI interrupt enable bit. 0: disable SPI interrupt This specification is subject to change without prior notice. 14 2002/03/01 EM78P451 OTP ROM 1: enable SPI interrupt • Bit 3 (TM1IE) TM1IE interrupt enable bit. 0: disable TM1IE interrupt 1: enable TM1IE interrupt • Bits 4~7 Not used. • Individual interrupt is enabled by setting its associated control bit in IOCF to "1". • The IOCF Register could be read and written. /WUE Oscillator Enable Disable /WUE Reset Q Q Clear P D R CLK C L VCC Set /WUE 8 from S/W P60~P67 VCC /WUE /PHEN 4 P74~P75, P90~P91 Fig. 5 Block Diagram of Sleep Mode and Wake-up Circuits on I/O Ports This specification is subject to change without prior notice. 15 2002/03/01 EM78P451 OTP ROM 4.3 TCC/WDT Presacler An 8-bit counter is available as prescaler for the TCC or WDT. The prescaler is available for either the TCC or WDT only at any given time, and the PAB bit of CONT register is used to determine the prescaler assignment. The PSR0~PSR2 bits determine the prescale ratio. The prescaler is cleared each time the instruction is written to TCC under TCC mode. The WDT and prescaler, when assigned to WDT mode, are cleared by the WDTC or SLEP instructions. Fig. 6 depicts the circuit diagram of TCC/WDT. • R1(TCC) is an 8-bit timer/counter. TCC will increase by one at every instruction cycle (without prescaler). • The watchdog timer is a free running on-chip RC oscillator. The WDT will keep running even when the oscillator driver has been turned off (i.e. in sleep mode). During normal operation or sleep mode, a WDT time-out (if enabled) will cause the device to reset. The WDT can be enabled or disabled any time during the normal mode by software programming (if Code Option bit ENWDT is "1"). Refer to WDTE bit of IOCE register. Without presacler, the WDT time-out period is approximately 18 ms 1. 4.4 I/O Ports The I/O registers, from Port 5 to Port 9, are bi-directional tri-state I/O ports. P60~P67, P74~P75, and P90~P91 provide internal pull-high. P60~P67, P74~P75, and P90~P95 provide programmable wake-up function through software. P76~P77 can have open-drain output by software control. P80~P81 are the R-option pins which are enabled by software. When the R-option function is used, it is recommended that P80 and P81 are used as output pins. During R-option enabled state, P80 and P81 must be programmed as input pins. If an external resistor is connected to P80 (P81) for the R-option function, the current consumption should be taken as an important factor in the applications for low power consideration. The I/O ports can be defined as "input" or "output" pins by the I/O control registers (IOC5~IOC9) under program control. The I/O registers and I/O control registers are both readable and writable. The I/O interface circuit is shown in Fig. 7. Note that the reading path source of input and output pins is different when reading the I/O port. 1 NOTE: Vdd = 5V, set up time period = 16.2ms ± 5% Vdd = 3V, set up time period = 18.0ms ± 5% This specification is subject to change without prior notice. 16 2002/03/01 EM78P451 OTP ROM Data Bus CLK(=Fosc/2) 1 M U X SYNC TCC(R1) 2 cycles 0 TCC overflow interrupt PAB 0 WDT 1 M U X 8- b i t C o u n t e r PSR0~PSR2 8 - to - 1 MUX 0 WDTE 1 PAB MUX (in IOCE) WDT timeout Fig. 6 Block Diagram of TCC WDT PCRD Q P D R Q C L Q P R CLK PCWR IOD PORT D C CLK Q 0 1 M U X PDWR L PDRD Fig. 7 (a) The Circuit of I/O Port and I/O Control Register This specification is subject to change without prior notice. 17 2002/03/01 EM78P451 OTP ROM PCRD VCC ROC Weakly Pull-up P D R CLK Q C L PORT Q Q P R D C CLK Q L 0 Rex* 1 M U X PCWR IOD PDWR PDRD *The Rex is 560K ohm external resistor Fig.7(b) The Circuit of I/O Port with R-option (P80, P81) 4.5 SERIAL PERIPHERAL INTERFACE MODE 1. Overview & Features Overview: Figures 8, 9, and 10 show how EM78P451 communicates with other devices through SPI module. If EM78P451 is a master controller, it sends clock through the SCK pin. A couple of 8-bit data are transmitted and received at the same time. However, if EM78P451is defined as a slave, its SCK pin could be programmed as an input pin. Data will continue to be shifted based on both the clock rate and the selected edge. Features: • Operation in either Master mode or Slave mode, • Three-wire or four-wire synchronous communication; that is, full duplex • Programmable baud rates of communication, • Programming clock polarity, (RD bit7) • Interrupt flag available for the read buffer full, This specification is subject to change without prior notice. 18 2002/03/01 EM78P451 OTP ROM • Up to 8 MHz ( maximum ) bit frequency, SDO SPIR Reg Reg SPIR SPIW SPIW Reg Reg /SS SDI SPIS Reg SPI Module Module SPI Bit 7 SCK Master Device Slave Device Fig. 8 SPI Master/Slave Communication SDI SDO SCK /SS Vdd Master P50 P51 P52 P53 SDO SDI SCK /SS SDO SDI SCK /SS SDO SDI SCK /SS SDO SDI SCK /SS Slave Device 1 Slave Device 2 Slave Device 3 Slave Device 4 Fig. 9 The SPI Configuration of Single-Master and Multi-Slave This specification is subject to change without prior notice. 19 2002/03/01 EM78P451 OTP ROM SDI SDO SCK /SS SDI SDO SCK /SS Master1 or Slave1 Master2 or P50 Slave6 P51 P50 P51 P52 P53 P52 P53 SDI SDO Slave 4 for Master1/2 SCK /SS SDO /SS Slave 3 for Master 1/2 SDI SCK SDO SDI SCK /SS SDO SDI SCK /SS Slave 2 for master 1 Slave 5 for Master 2 Fig. 10 The SPI Configuration of Single-Master and Multi-Slave This specification is subject to change without prior notice. 20 2002/03/01 EM78P451 OTP ROM 2. SPI Function Description Read RBF RBFI Write SPIR SE reg SPIW reg Set to 1 Buffer Full Detector shift right SPIS reg P92/SDI bit 0 bit 7 SPIC reg P93/SDO Edge Select SBR0 ~SBR2 P95/ /SS SBR2~SBR0 8 / SS Tsco Noise Filter Clock Select 2 Prescaler 4, 8, 16, 32, 64 Edge Select P94/SCK TMR1/2 SPIC bit6 Fig. 11 SPI Block Diagram SPI SPI Read Register (0X0A) /SS SPI Write Register (0X0B) 8-1 MUX SPI Mode Select Register SDO SDI Shift Clock SPI Shift Buffer FOSC 2 1 0 SPIC 7~0 SPIWB 1 0 7 6 4 1 0 T1CON SPIC SPIS 2 4 INTC SPIC 7~0 SPIRB DATA BUS Fig. 12 The Function Block Diagram of SPI Transmission This specification is subject to change without prior notice. 21 2002/03/01 EM78P451 OTP ROM The following describes the function of each block and explains how to carry out the SPI communication with the signals depicted in Fig.11 and Fig.12: • P92/SDI: Serial Data In. • P93/SDO: Serial Data Out. • P94/SCK: Serial Clock. • P95//SS: /Slave Select (Option). This pin (/SS) may be required during a slave mode. • RBF: Set by Buffer Full Detector, and reset in software. • RBIF: Set by Buffer Full Detector, and reset in software. • Buffer Full Detector: Sets to 1 when an 8-bit shifting is completed. • SSE: Loads the data in SPIS register, and begin to shift • SPIS reg.: Shifting byte in and out. The MSB is shifted first. Both the SPIS register and the SPIW register are loaded at the same time. Once data are written, SPIS starts transmission / reception. The received data will be moved to the SPIR register as the shifting of the 8-bit data is completed. The RBF (Read Buffer Full) flag and the RBFI(Read Buffer Full Interrupt) flag are then set. • SPIR reg.: Read buffer. The buffer will be updated as the 8-bit shifting is completed. The data must be read before the next reception is completed. The RBF flag is cleared as the SPIR register reads. • SPIW reg.: Write buffer. The buffer will deny any attempt to write until the 8-bit shifting is completed. The SSE bit will be kept in 1 if the communication is still undergoing. This flag must be cleared as the shifting is completed. Users can determine if the next write attempt is available. • SBRS2~SBRS0: Programming the clock frequency/rates and sources. • Clock Select: Selecting either the internal or external clock as the shifting clock. • Edge Select: Selecting the appropriate clock edges by programming the CES bit 3. SPI Signal & Pin Description The detailed functions of the four pins, SDI, SDO, SCK, and /SS, which are shown in Fig. 9, are as follows: SDI/P92 (Pin 7): • Serial Data In, • Receive serially, the Most Significant Bit (MSB) first, Least Significant Bit (LSB) last, • Defined as high-impedance, if not selected, • Program the same clock rate and clock edge to latch on both the master and slave devices, This specification is subject to change without prior notice. 22 2002/03/01 EM78P451 OTP ROM • The received byte will update the transmitted byte, • Both the RBF and RBFIF bits (located in Register 0x0C) will be set as the SPI operation is completed. • Timing is shown in Fig.13 and14. SDO/P93 (Pin 8): • Serial Data Out, • Transmit serially; the Most Significant Bit (MSB) first, Least Significant Bit (LSB) last, • Program the same clock rate and clock edge to latch on both the master and slave devices, • The received byte will update the transmitted byte, • The CES (located in Register 0x0D) bit will be reset, as the SPI operation is completed. • Timing is shown in Fig.13 and 14. SCK/P94 (Pin 9): • Serial Clock • Generated by a master device • Synchronize the data communication on both the SDI and SDO pins • The CES (located in Register 0x0D) is used to select the edge to communicate. • The SBR0~SBR2 (located in Register 0x0D) is used to determine the baud rate of communication • The CES, SBR0, SBR1, and SBR2 bits have no effect in the slave mode • Timing is show in Fig.13 and 14 /SS/P95 (Pin 10): • Slave Select; negative logic, • Generated by a master device to signify the slave(s) to receive data, • Goes low before the first cycle of SCK appears, and remains low until the last (eighth) cycle is completed, • Ignores the data on the SDI and SDO pins while /SS is high, because the SDO is no longer driven. • Timing is shown in Fig.13 and Fig. 14. This specification is subject to change without prior notice. 23 2002/03/01 EM78P451 OTP ROM 4. Programmed the related registers As the SPI mode is defined, the related registers of this operation are shown in Table 2 and Table 3. Table 2 Related Control Registers of the SPI Mode Address Name 0x0D *SPIC/RD 0x0F INTC/IOCF Bit 7 CES -- Bit 6 SPIE -- Bit 5 SRO -- Bit 4 SSE -- Bit 3 -TM1IE Bit 2 SBR2 SPIIE Bit 1 SBR1 EXIE Bit 0 SBR0 TCIE • SPIC: SPI Control Register. • CES (bit 7): Clock Edge Select bit 1 = Data shifts out on falling edge, and shifts in on rising edge. Data is on hold during the high level. 0 = Data shifts out on rising edge, and shifts in on falling edge. Data is on hold during the low level. • SPIE (bit 6):SPI Enable bit 1 = Enable SPI mode 0 = Disable SPI mode • SRO (bit 5):SPI Read Overflow bit 1 = A new data is received while the previous data is still being on hold in the SPIB register. Under this condition, the data in SPIS register will be destroyed. To avoid setting this bit, users should read the SPIRB register even if the transmission is implemented only. 0 = No overflow. <Note>:This can only occur under slave mode. • SSE (bit 4):SPI Shift Enable bit 1 = Start to shift, and stays on 1 while the current byte continues to transmit. 0 = Reset as soon as the shifting is completed and the next byte is ready to shift. <Note>: This bit can be reset by hardware only. • SBRS (bit 2~0): SPI Baud Rate Select Bits SBRS2 (Bit 2) 0 0 0 0 1 1 1 1 <Note> SBRS1 (Bit 1) 0 0 1 1 0 0 1 1 SBRS0 (Bit 0) 0 1 0 1 0 1 0 1 Mode Master Master Master Master Master Slave Slave Master Baud Rate Fsco/2 Fsco/4 Fsco/8 Fsco/16 Fsco/32 /SS enable /SS disable TMR1/2 In master mode, /SS is disable. • INTC: Interrupt control register This specification is subject to change without prior notice. 24 2002/03/01 EM78P451 OTP ROM • Bit 3 (TM1IE) TM1IE interrupt enable bit. 0: disable TM1IE interrupt 1: enable TM1IE interrupt • Bit 2 (SPIIE) SPI interrupt enable bit. 0: disable SPI interrupt 1: enable SPI interrupt • Bit 1 (EXIE) EXIF interrupt enable bit. 0: disable EXIF interrupt 1: enable EXIF interrupt • Bit 0 (TCIE) TCIF interrupt enable bit. 0: disable TCIF interrupt 1: enable TCIF interrupt Table 3 Related Status/Data Registers of the SPI Mode Address 0X0A 0x0B 0x0C Name SPIRB/RA SPIWB/RB SPIS/RC Bit 7 SRB7 SWB7 0 Bit 6 SRB6 SWB6 0 Bit 5 SRB5 SWB5 0 Bit 4 SRB4 SWB4 TM1IF Bit 3 SRB3 SWB3 OD3 Bit 2 SRB2 SWB2 OD4 Bit 1 SRB1 SWB1 RBFIF Bit 0 SRB0 SWB0 RBF • SPIRB: SPI Read Buffer. Once the serial data is received completely, it will load to SPIRB from SPISR. The RBF bit and the RBFIF bit in the SPIS register will be set also. • SPIWB: SPI Write Buffer. As a transmitted data is loaded, the SPIS register stands by and start to shift the data when sensing SCK edge with SSE set to “1”. • SPIS: SPI Status register • TM1IF (bit 4):Timer1 interrupt flag. • OD3 (bit 3):Open-Drain Control bit (P93) 1 = Open-drain enable for SDO, 0 = Open-drain disable for SDO. • OD4 (bit 2):Open Drain-Control bit (P94) 1 = Open-drain enable for SCK, 0 = Open-drain disable for SCK. • RBFIF (bit 1):Read Buffer Full Interrupt flag 1 = Receive is completed, SPIB is full, and an interrupt occurs if enabled. 0 = Receive is ongoing, SPIB is empty. • RBF (bit 0):Read Buffer Full flag 1 = Receive is completed, SPIB is full. This specification is subject to change without prior notice. 25 2002/03/01 EM78P451 OTP ROM 0 = Receive is ongoingt, SPIB is empty. 5. SPI Mode Timing The edge of SCK is selected by programming bit CES. The waveform shown in Fig.13 is applicable regardless of whether the EM78P451 is under master or slave mode with /SS disabled. However, The waveform in Fig. 14 can only be implemented in slave mode with /SS enabled. Fig. 13 SPI Mode with /SS Disable Fig. 14 This specification is subject to change without prior notice. SPI Mode with /SS Enable 26 2002/03/01 EM78P451 OTP ROM 6. Software Application of SPI Example for SPI: For Master ORG 0X0 SETTING: CLRA IOW 0X05 ;SET PORT5 OUTPUT IOW 0X06 ;SET PORT6 OUTPUT MOV 0X05,A MOV A,@0B11001111 ;SET PRESCALER FOR WDT CONTW MOV A,@0B00010001 ;DISABLE WAKEUP FUNCTION IOW 0X0E MOV A,@0B00000000 ;DISABLE INTERRUPT IOW 0X0F MOV A,@0X07 ;SDI INPUT AND SDO, SCK OUTPUT IOW 0X09 MOV A,@0B10000000 ;CLEAR RBF AND RBFIF FLAG MOV 0X0C,A MOV A,@0B11100000 ;SELECT CLOCK EDGE AND ENABLE SPI MOV 0X0D,A START: WDTC BC 0X0C,1 ;CLEAR RBFIF FLAG MOV A,@0XFF MOV 0X05,A ;SHOW A SIGNAL AT PORT5 MOV 0X0A,A ;MOVE FF AT READ BUFFER MOV A,@0XAA ;MOVE AA AT WRITE BUFFER MOV 0X0B,A BS 0X0D,4 ;START TO SHIFT SPI DATA NOP JBC 0X0D,4 ;POLLING LOOP FOR CHECKING SPI TRANSMISSION COMPLETED JMP $-2 This specification is subject to change without prior notice. 27 2002/03/01 EM78P451 OTP ROM BC 0X03,2 CALL DELAY ;TO CATCH THE DATA FROM SLAVER MOV A,0X0A XOR A,@0X5A ;COMPARE THE DATA FROM SLAVER JBS 0X03,2 JMP START FLAG: MOV A,@0X55 ;SHOW THE SIGNAL WHEN RECEIVING CORRECT DATA FROM SLAVER MOV 0X05,A CALL DELAY JMP START DELAY: ; (USER’S PROGRAM) EOP ORG 0XFFF JMP SETTING This specification is subject to change without prior notice. 28 2002/03/01 EM78P451 OTP ROM For Slaver ORG 0X0 INITI: JMP INIT ORG 0X2 INTERRUPT: ;INTERRUPT ADDRESS MOV A,@0X55 MOV 0X06,A ;SHOW A SIGNAL AT PORT 6 WHEN ENTERING INTERRUPT MOV A,@0B11100110 ;ENABLE SPI, /SS DISABLED MOV 0X0D,A BS 0X0D,4 ;KEEP SSE AT 1 TO WAIT FOR SCK SIGNAL IN ORDER TO SHIFT DATA MOV A,@0X00 ;MOVE 00 TO WRITE BUFFER IN ORDER TO KEEP MASTER’S READ BUFFER AS 00 MOV 0X0B,A BS 0X0D,4 ;KEEP SSE AT 1 TO WAIT FOR SCK SIGNAL IN ORDER TO SHIFT DATA NOP JBC 0X0D,4 ;POLLING LOOP FOR CHECKING SPI TRANSMISSION COMPLETED JMP $-2 BS 0X0D,4 ;KEEP SSE AT 1 TO WAIT FOR SCK SIGNAL IN ORDER TO SHIFT DATA BC 0X03,2 MOV A,0X0A MOV 0X06,A ;READ MASTER’S DATA FROM READ BUFFER XOR A,@0XAA ;CHECK PASS SIGNAL FROM READ BUFFER JBS 0X03,2 JMP $-6 JMP SPI ORG 0X30 INIT: CLRA IOW 0X05 IOW 0X06 MOV 0X05,A MOV 0X06,A This specification is subject to change without prior notice. 29 2002/03/01 EM78P451 OTP ROM MOV A,@0XFF IOW 0X08 MOV A,@0B11001111 ;SET PRESCALER FOR WDT CONTW MOV A,@0B00010001 ;DISABLE WAKEUP FUNCTION IOW 0X0E MOV A,@0B00000010 ;ENABLE EXTERNAL INTERRUPT IOW 0XF ENI MOV A,@0B00110111 IOW 0X09 BC 0X3F,1 ;CLEAR RBFIF FLAG NOP JBS 0X3F,1 ;POLLING LOOP FOR CHECKING INTERRUPT OCCURENCE JMP $-2 JMP INTERRUPT SPI: BS 0X0D,4 ;KEEP SSE ENABLED AS LONG AS POSSIBLE WDTC MOV A,@0X0F ;SHOW A SIGNAL WHEN ENTERING SPI LOOP MOV 0X06,A JBC 0X08,1 ;CHOOSE P81 AS A SIGNAL BUTTON JMP SPI MOV A,@0X5A ;MOVE 5A INTO WRITE BUFFER WHEN P81 BUTTON IS PUSHED MOV 0X0B,A NOP JBC 0X0D,4 ;POLLING LOOP FOR CHECKING SPI TRANSMISSION COMPLETED JMP $-2 BS 0XD,4 NOP NOP MOV A,@0XF0 ;DISPLAY AT PORT6 WHEN P81 BUTTON IS PUSHED MOV 0X06,A MOV A,@0X00 ;SEND A SIGNAL TO MASTER TO PREVENT INFINITE LOOP This specification is subject to change without prior notice. 30 2002/03/01 EM78P451 OTP ROM MOV 0X0B,A NOP JBC 0X0D,4 JMP $-2 BS 0X0D,4 BS 0X0C,7 BC 0X0C,1 NOP JMP SPI DELAY: ; (USER’S PROGRAM) EOP ORG 0XFFF JMP INITI This specification is subject to change without prior notice. 31 2002/03/01 EM78P451 OTP ROM 4.6 Timer 1 1. Overview Timer1(TMR1) is an eight-bit clock counter with a programmable prescaler. It is designed for the SPI module as a baud rate clock generator. TMR1 can be read and written and cleared on any reset conditions. If employed, it can be turned down for power saving by setting TMR1EN bit [T1CON<2>] to 0. 2. Function description Fig. 15 shows TIMER1 block diagram. Each signal and block is described as follows: Fig. 15 TIMER1 Block Diagram • OSC/4: Input clock. • Prescaler: Option of 1:1, 1:4, 1:8, and 1:16 defined by T1P1 and T1P02 (T1CON<1, 0>). It is cleared when a value is written to TMR1 or T1CON, and during any kind of reset as well. • PWP: Pulse width preset register. The desired width of baud clock is written in advance. • TMR1: Timer 1 register. TMR1 increases until it matches with PWP, and then resets to 0. If it is chosen optionally in the SPI mode, its output is fed as a shifting clock. • Comparator: To change the output status while a match occurs. The TMR1IF flag will be set at the same time. 3. Programmed the related registers The related registers of the defining TMR1 operation are shown in Table 4 and Table 5 This specification is subject to change without prior notice. 32 2002/03/01 EM78P451 OTP ROM Table 4 Related Control Registers of the TMR1 Address Name 0x0C SPIS/RC 0x0F INTC/IOCF Bit 7 0 0 Bit 6 0 0 Bit 5 0 0 Bit 4 TM1IF 0 Bit 3 OD3 TM1IE Bit 2 OD4 SPIIE Bit 1 RBFIF EXIE Bit 0 RBF TCIE Bit 4 TMR14 PWP4 0 Bit 3 TMR13 PWP3 0 Bit 2 TMR12 PWP2 TM1E Bit 1 TMR11 PWP1 TM1P1 Bit 0 TMR10 PWP0 TM1P0 Table 5 Related Status/Data Registers ofTMR1 Address Name Bit 7 0X0E TMR1/RE TMR17 0x0F PWP/RF PWP7 0x0C T1CON/IOCC 0 Bit 6 TMR16 PWP6 0 Bit 5 TMR15 PWP5 0 • TMR1: Timer1 Register TMR17~TMR10 is bit set of Timer1 register and it increases until the value matches PWP and then it reset to 0. • PWP: Pulse Width Preset Register PWP7~PWP0 is bit set of pulse width preset for the desired width of baud clock in advance. • T1CON: Timer1 Control Register TM1E (bit2): Timer1 enable bit TM1P1 and TM1P0 (bit1~0): Timer1 prescaler for FSCO TM1P1 TM1P0 Prescaler Rate 0 0 1:1 0 1 1:4 1 0 1:8 1 1 1:16 This specification is subject to change without prior notice. 33 2002/03/01 EM78P451 OTP ROM 4.7 RESET and Wake-up A RESET is initiated by (1) Power on reset, or (2) WDT timeout. (if enabled) VDD D Oscillator Q CLK CLK CLR Poweron Reset Voltage Detector WDTE Setup Time WDT timeout WDT Reset Fig. 16 Block Diagram of Reset The device is kept in a RESET condition for a period of approx. 18ms 1 (one oscillator start-up timer period) after the reset is detected and Fig.16 is the block diagram of reset. Once the RESET occurs, the following functions are performed. • The oscillator is running, or will be started. • The Program Counter (R2) is set to all "1". • When power is switched on, bits 5~6 of R3 and the upper 2 bits of R4 are cleared. • All I/O port pins are configured as input mode (high-impedance state). • The Watchdog timer and prescaler are cleared. • The Watchdog timer is enabled if Code Option bit ENWDT is "1". • The CONT register is set to all "1" except bit 6 (INT flag). • Bits 3,6 of IOCE register are cleared, bits 0,4~5 of IOCE register are set to "1". 1 NOTE: Vdd = 5V, set up time period = 16.2ms ± 5% Vdd = 3V, set up time period = 18.0ms ± 5% This specification is subject to change without prior notice. 34 2002/03/01 EM78P451 OTP ROM • Bits 0 of R3F and bits 0 of IOCF registers are cleared. The sleep mode (power down) is achieved by executing the SLEP instruction (named as SLEEP1 MODE). While entering sleep mode, the WDT (if enabled) is cleared but keeps on running. The controller is awakened by WDT timeout (if enabled), and it will cause the controller to reset. The T and P flags of R3 are used to determine the source of the reset (wake-up). In addition to the basic SLEEP1 MODE, EM78P451 has another sleep mode (caused by clearing "SLPC" bit of IOCE register, designated as SLEEP2 MODE). In the SLEEP2 MODE, the controller can be awakened by(a) Any one of the wake-up pins is set to “0.” (refer to Fig.17). Upon waking, the controller will continue to execute the program in-line. In this case, before entering SLEEP2 MODE, the wake-up function of the trigger sources (P60~P67, P74~P75, and P90~P91)should be selected (e.g. input pin) and enabled (e.g. pull-high, wake-up control). One caution should be noted is that after waking up, the WDT is enabled if Code Option bit ENWDT is "1". The WDT operation (to be enabled or disabled) should be appropriately controlled by software after waking up. (b) WDT time-out (if enabled). On wake-up, will cause the controller reset. Table 6 The Summary of the Initialized Values for Registers Address Name N/A IOC5 N/A IOC6 N/A IOC7 N/A IOC8 N/A IOC9 N/A CONT Reset Type Bit 7 Bit 6 Bit Name C57 C56 Power-On 1 1 /RESET and WDT 1 1 Wake-Up from Pin Change P P Bit Name C67 C66 Power-On 1 1 /RESET and WDT 1 1 Wake-Up from Pin Change P P Bit Name C77 C76 Power-On 1 1 /RESET and WDT 1 1 Wake-Up from Pin Change P P Bit Name C87 C86 Power-On 1 1 /RESET and WDT 1 1 Wake-Up from Pin Change P P Bit Name C97 C96 Power-On 1 1 /RESET and WDT 1 1 Wake-Up from Pin Change P P Bit Name /PHEN /INT Power-On 1 0 /RESET and WDT 1 P Wake-Up from Pin Change P P Bit Name - This specification is subject to change without prior notice. 35 Bit 5 C55 1 1 P C65 1 1 P C75 1 1 P C85 1 1 P C95 1 1 P 1 1 P - Bit 4 C54 1 1 P C64 1 1 P C74 1 1 P C84 1 1 P C94 1 1 P 1 1 P - Bit 3 C53 1 1 P C63 1 1 P C73 1 1 P C83 1 1 P C93 1 1 P PAB 1 1 P - Bit 2 Bit 1 Bit 0 C52 C51 C50 1 1 1 1 1 1 P P P C62 C61 C60 1 1 1 1 1 1 P P P C72 C71 C70 1 1 1 1 1 1 P P P C82 C81 C80 1 1 1 1 1 1 P P P C92 C91 C90 1 1 1 1 1 1 P P P PSR2 PSR1 PSR0 1 1 1 1 1 1 P P P 2002/03/01 EM78P451 OTP ROM 0x00 0x01 0x02 0x03 0x04 0x05 0x06 0x07 0x08 0x09 0x0A 0x0B 0x0C R0(IAR) Power-On U U U U U U U U /RESET and WDT P P P P P P P P Wake-Up from Pin Change P P P P P P P P Bit Name R1(TCC) Power-On 0 0 0 0 0 0 0 0 /RESET and WDT 0 0 0 0 0 0 0 0 Wake-Up from Pin Change P P P P P P P P Bit Name R2(PC) Power-On 1 1 1 1 1 1 1 1 /RESET and WDT 1 1 1 1 1 1 1 1 Wake-Up from Pin Change **P **P **P **P **P **P **P **P Bit Name GP PS1 PS0 T P Z DC C R3(SR) Power-On 0 0 0 t t U U U /RESET and WDT 0 0 0 t t P P P Wake-Up from Pin Change P P P t t P P P Bit Name RSR.1 RSR.0 R4(RSR) Power-On 0 0 U U U U U U /RESET and WDT 0 0 P P P P P P Wake-Up from Pin Change P P P P P P P P Bit Name P57 P56 P55 P54 P53 P52 P51 P50 R5(P5) Power-On U U U U U U U U /RESET and WDT P P P P P P P P Wake-Up from Pin Change P P P P P P P P Bit Name P67 P66 P65 P64 P63 P62 P61 P60 R6(P6) Power-On U U U U U U U U /RESET and WDT P P P P P P P P Wake-Up from Pin Change P P P P P P P P Bit Name P77 P76 P75 P74 P73 P72 P71 P70 R7(P7) Power-On U U U U U U U U /RESET and WDT P P P P P P P P Wake-Up from Pin Change P P P P P P P P Bit Name P87 P86 P85 P84 P83 P82 P81 P80 R8(P8) Power-On U U U U U U U U /RESET and WDT P P P P P P P P Wake-Up from Pin Change P P P P P P P P Bit Name P97 P96 P95 P94 P93 P92 P91 P90 R9(P9) Power-On U U U U U U U U /RESET and WDT P P P P P P P P Wake-Up from Pin Change P P P P P P P P Bit Name SRB7 SRB6 SRB5 SRB4 SRB3 SRB2 SRB1 SRB0 RA(SPIRB) Power-On U U U U U U U U /RESET and WDT P P P P P P P P Wake-Up from Pin Change P P P P P P P P Bit Name SWB7 SWB6 SWB5 SWB4 SWB3 SWB2 SWB1 SWB0 RB(SPIWB) Power-On U U U U U U U U /RESET and WDT P P P P P P P P Wake-Up from Pin Change P P P P P P P P ENSD Bit Name OBDC IBDC TIIF OD3 OD4 RBFIF RBF O RC(SPIS) Power-On 0 0 0 0 0 0 0 0 /RESET and WDT 0 0 0 0 0 0 0 0 Wake-Up from Pin Change P P P P P P P P SBRS SBRS SBRS Bit Name CES SPIE SRO SPISE 2 1 0 This specification is subject to change without prior notice. 36 2002/03/01 EM78P451 OTP ROM 0x0D RD(SPIC) Power-On /RESET and WDT Wake-Up from Pin Change Bit Name 0x0E RE(TMR1) 0x0F RF(PWP) 0x3F R3F(ISR) 0x0C IOCC 0x0D IOCD 0x0E IOCE 0x0F IOCF 0x10~0x3E GPR Power-On /RESET and WDT Wake-Up from Pin Change Bit Name Power-On /RESET and WDT Wake-Up from Pin Change Bit Name Power-On /RESET and WDT Wake-Up from Pin Change Bit Name Power-On /RESET and WDT Wake-Up from Pin Change Bit Name Power-On /RESET and WDT Wake-Up from Pin Change Bit Name Power-On /RESET and WDT Wake-Up from Pin Change Bit Name Power-On /RESET and WDT Wake-Up from Pin Change Bit Name Power-On /RESET and WDT Wake-Up from Pin Change 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P P P P P P P TMR1 TMR1 TMR1 TMR1 TMR1 TMR1 TMR1 7 6 5 4 3 2 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P P P P P P P PWP7 PWP6 PWP5 PWP4 PWP3 PWP2 PWP1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 P P P P P P P T1IF SPIIF EXIF U U U U 0 0 0 U U U U 0 0 0 U U U U P P P T1E T1P1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 P P P P P P P S7 /PU9 /PU8 /PU6 1 1 1 1 1 1 1 1 1 1 1 1 1 1 P P P P P P P ODE WTE SLPC ROC U 0 1 1 0 U U U 0 1 1 0 U U U P 1 1 P U U T1IE SPIIE EXIE U U U U 0 0 0 U U U U 0 0 0 U U U U P P P U U U U U U U P P P P P P P P P P P P P P 0 0 P TMR1 0 0 0 P PWP0 1 1 P TCIF 0 0 P T1P0 0 0 P /PU5 1 1 P /WUE 1 1 P TCIE 0 0 P U P P ** To execute the next instruction after the ”SLPC” bit status of IOCE register being on high-to-low transition. X: Not used. U: Unknown or don’t care.P: Previous value before reset. t: Check Table 7 The Status of RST, T, and P of STATUS Register A RESET condition is initiated by the following events: 1. A power-on condition, 2. Watchdog timer time-out. The values of T and P, listed in Table 7 are used to check how the processor wakes up. Table 8 shows the events that may affect the status of T and P. This specification is subject to change without prior notice. 37 2002/03/01 EM78P451 OTP ROM Table 7 The Values of RST, T and P After RESET Reset Type Power on WDT during Operating mode WDT wake-up during SLEEP1 mode WDT wake-up during SLEEP2 mode Wake-Up on pin change during SLEEP2 mode T 1 0 0 0 P P 1 P 0 P P *P: Previous value before reset Table 8 The Status of RST, T and P Being Affected by Events Event Power on WDTC instruction WDT time-out SLEP instruction Wake-Up on pin change during SLEEP2 mode T 1 1 0 1 P P 1 1 *P 0 P *P: Previous value before reset 4.8 Interrupt The EM78P451 has the following interrupts. 1. /TCC overflow interrupt 2. External interrupt (/INT) 3. Serial Peripheral Interface (SPI) transmission completed interrupt. 4. Timer1 comparator completed interrupt. R3F is the interrupt status register, which records the interrupt request in flag bit. IOCF is the interrupt mask register. Global interrupt is enabled by ENI instruction and is disabled by DISI instruction. When one of the interrupts (if enabled) is generated, will cause the next instruction to be fetched from address 001H. Once in the interrupt service routine the source of the interrupt can be determined by polling the flag bits in the R3F register. The interrupt flag bit must be cleared by software before leaving the interrupt service routine and enabling interrupts to avoid recursive interrupts. The flag in the Interrupt Status Register (R3F) is set regardless of the status of its mask bit or the execution of ENI instruction. Note that reading R3F will obtain the output of logic AND of R3F and IOCF (refer to Fig. 17). The RETI instruction exits interrupt routine and enables the global interrupt (execution of ENI instruction). When an interrupt is generated by INT instruction (if enabled), it causes the next instruction to be This specification is subject to change without prior notice. 38 2002/03/01 EM78P451 OTP ROM fetched from address 002H. IRQn P Q R CLK C L Q D /IRQn R3F ENI/DISI Q Q RESET interrupt IRQm RFRD P D R C CLK L IOD IOCFWR IOCF IOCFRD RFWR Fig. 17 Interrupt Input Circuit 4.9 Oscillator 1. Oscillator Modes The EM78P451 can operate in four different oscillator modes. There are high XTAL (HXT) oscillator mode, low XTAL (LXT) oscillator mode, External RC oscillator mode (ERC), and Internal C、External R oscillator modes. User can select one of them by programming MS, RCT, IRC, HLF and HLP in the Code Option Register. Table 9 depicts how these three modes are defined. Table 9 Oscillator Modes by MS, IRC, RCT. Mode High XTAL Oscillator Low XTAL Oscillator External RC Oscillator External R and Internal C Oscillator MS 1 1 0 0 IRC X X 1 1 RCT X X 1 0 HLF 1 0 X X HLP X 0 X X <Note> X: Don’t care 2. Crystal Oscillator/Ceramic Resonators (XTAL) EM78P451 can be driven by an external clock signal through the OSCI pin as shown in Fig 18 below. In the most applications, pin OSCI and pin OSCO is connected with a crystal or ceramic resonator to generate oscillation. Fig 19 depicts such circuit. Table 10 provides the recommended values of C1 This specification is subject to change without prior notice. 39 2002/03/01 EM78P451 OTP ROM and C2. Since each resonator has its own attribute, user should refer to its specification for appropriate values of C1 and C2. RS, a serial resistor may be necessary for AT strip cut crystal or low frequency mode. OSCI Ext. Clock OSCO EM78P451 Fig. 18 Circuit for External Clock Input C1 OSCI EM78P451 XTAL OSCO RS C2 Fig. 19 Circuit for Crystal/Resonator Table 10 Capacitor Selection Guide for Crystal Oscillator Ceramic Resonators Oscillator Type Frequency Mode Ceramic Resonator HXT LXT Crystal Oscillator HXT This specification is subject to change without prior notice. Frequency 455 KHz 1.0 MHz 2.0 MHz 4.0 MHz 32.768 KHz 100 KHz 200 KHz 455 KHz 1.0 MHz 2.0 MHz 4.0 MHz 40 C1 (pF) 10~150 40~80 20~40 10~30 25 25 25 20~40 15~30 15 15 C2 (pF) 10~150 40~80 20~40 10~30 15 25 25 20~150 15~30 15 15 2002/03/01 EM78P451 OTP ROM 330 330 C OSCI 7404 7404 7404 EM78P451 XTAL Fig. 20 Circuit for Crystal/Resonator-Series Mode 4.7K 10K VDD OSCI 7404 7404 EM78P451 10K XTAL C1 C2 Fig. 21 Circuit for Crystal/Resonator-Parallel Mode 3. RC Oscillator Mode For some applications that do not need a very precise timing calculation, the RC oscillator (Fig 22 & Fig 23) offers a lot of cost savings. Nevertheless, it should be noted that the frequency of the RC oscillator is influenced by the supply voltage, the values of the resistor (Rext), the capacitor (Cext), and even by the operation temperature. Moreover, the frequency also changes slightly from one chip to another due to the manufacturing process variation. In order to maintain a stable system frequency, the values of the Cext should not be less than 20pF, and that the value of Rext should not be greater than 1 M ohm. If they cannot be kept in this range, the frequency is easily affected by noise, humidity, and leakage. The smaller the Rext in the RC oscillator, the faster its frequency will be. On the contrary, for very low This specification is subject to change without prior notice. 41 2002/03/01 EM78P451 OTP ROM Rext values, for instance, 1 KΩ, the oscillator becomes unstable because the NMOS cannot discharge the current of the capacitance correctly. Based on the reasons above, it must be kept in mind that all of the supply voltage, the operation temperature, the components of the RC oscillator, the package types, the way the PCB is layout, will affect the system frequency. VCC Rext OSCI Cext EM78P451 Fig. 22 Circuit for External RC Oscillator Mode VCC Rext OSCI EM78P451 Fig. 23 Circuit for External R, Internal C Oscillator Mode Calibrate frequency of External RC oscillator (For reference only) C ext 20pF 100pF R ext 3.3K 5.1K 10K 100K 3.3K 5.1K 10K 100K This specification is subject to change without prior notice. Fosc @5.0V,25℃ 3.4MHz 2.2MHz 1.3MHz 144KHz 1.39MHz 935KHz 500KHz 54.5KHz 42 2002/03/01 EM78P451 OTP ROM 3.3K 5.1K 10K 100K 300pF 740KHz 490KHz 255KHz 28KHz Internal C, external R Table (For reference only) External R (Ohm) Fosc @5.0V, 25℃ (Hz) 10K 15K 20K 30K 12M 7.7M 5.7M 3.65M 51K 100K 150K 200K 2.24M 1.14M 749K 559K 510K 2M 3.3M 214K 56K 32.8K 4.10. Code Option Register : Address 0xFFF 12 MS 11 10 ENWDT CLKS 9 PTB 8 HLF 7 RCT 6 HLP 5 4 DEL0 DEL1 3 ID3 2 ID2 1 ID1 0 ID0 • Bit 12 (MS): Oscillator type selection. 0: RC type 1: XTAL type • Bit 11 (ENWDT): Watchdog Timer enabled. 0: Enable 1: Disable • Bit 10 (CLKS): Clocks of each instruction cycle. 0: Two clocks 1: Four clocks • Bit 9 (PTB): Protect bit. 0: Protect enabled 1: Protect disabled • Bit 8 (HLF): XTAL frequency selection. 0: Low frequency (32.768KHz) 1: High frequency This bit is useful only when Bit 12 (MS) is 1. When MS is 0, HLF must be 0. This specification is subject to change without prior notice. 43 2002/03/01 EM78P451 OTP ROM • Bit 7 (RCT): Resistor Capacitor. 0: internal RC 1: external RC • Bit 6 (HLP): Power consumption selection. 0: Low power 1: High power • Bit 5 ~ Bit 4: DEL1 and DEL0 (SDI) input delay time options. DEL 1 1 0 1 DEL 0 1 1 0 Delay time 0 ns 50 ns 100 ns • Bit3~0 (ID): User’s ID code. • Procedures to configure the RC oscillators by programming the option code: i. Enable External RC oscillator: MS (0) -> IRC (1) -> RCT (1) ii. Enable External R and Internal C oscillator: •MS (0) -> IRC (1) -> RCT (0) 4.11 Instruction Set Each instruction in the instruction set is a 13-bit word divided into an OP code and one or more operands. All instructions are executed within one single instruction cycle (consisting of 2 oscillator periods), unless the program counter is changed by(a) Executing the instruction "MOV R2,A", "ADD R2,A", "TBL", or any other instructions that write to R2 (e.g. "SUB R2,A", "BS R2,6", "CLR R2", ⋅⋅⋅⋅). (b) execute CALL, RET, RETI, RETL, JMP, Conditional skip (JBS, JBC, JZ, JZA, DJZ, DJZA) which were tested to be true. Under these cases, the execution takes two instruction cycles. In addition, the instruction set has the following features: (1). Every bit of any register can be set, cleared, or tested directly. (2). The I/O register can be regarded as general register. That is, the same instruction can operate on I/O register. The symbol "R" represents a register designator that specifies which one of the registers (including operational registers and general purpose registers) is to be utilized by the instruction. Bits 6 and 7 in R4 determine the selected register bank. "b" represents a bit field designator that selects the value for This specification is subject to change without prior notice. 44 2002/03/01 EM78P451 OTP ROM the bit located in the register "R" and affects operation. "k" represents an 8 or 10-bit constant or literal value. HEX 0000 0001 0002 0003 0004 000r 0010 0011 0012 MNEMONIC NOP DAA CONTW SLEP WDTC IOW R ENI DISI RET 0 0000 0001 0011 0013 RETI 0 0000 0001 0100 0 0000 0001 rrrr 0014 001r CONTR IOR R 0 0000 0010 0000 0020 TBL 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 00rr 0080 00rr 01rr 01rr 01rr 01rr 02rr 02rr 02rr 02rr 03rr 03rr 03rr 03rr 04rr 04rr 04rr 04rr 05rr 05rr 05rr 05rr MOV R,A CLRA CLR R SUB A,R SUB R,A DECA R DEC R OR A,R OR R,A AND A,R AND R,A XOR A,R XOR R,A ADD A,R ADD R,A MOV A,R MOV R,R COMA R COM R INCA R INC R DJZA R DJZ R 0 0110 00rr rrrr 06rr RRCA R 0 0110 01rr rrrr 06rr RRC R 0 0110 10rr rrrr 06rr RLCA R 0 0110 11rr rrrr 06rr RLC R 0 0111 00rr rrrr 07rr SWAPA R 0 0 0 0 0 0 0 0 0 INSTRUCTION BINARY 0000 0000 0000 0000 0000 0001 0000 0000 0010 0000 0000 0011 0000 0000 0100 0000 0000 rrrr 0000 0001 0000 0000 0001 0001 0000 0001 0010 0000 0000 0000 0001 0001 0001 0001 0010 0010 0010 0010 0011 0011 0011 0011 0100 0100 0100 0100 0101 0101 0101 0101 01rr 1000 11rr 00rr 01rr 10rr 11rr 00rr 01rr 10rr 11rr 00rr 01rr 10rr 11rr 00rr 01rr 10rr 11rr 00rr 01rr 10rr 11rr rrrr 0000 rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr rrrr This specification is subject to change without prior notice. OPERATION No Operation Decimal Adjust A A → CONT 0 → WDT, Stop oscillator 0 → WDT A → IOCR Enable Interrupt Disable Interrupt [Top of Stack] → PC [Top of Stack] → PC, Enable Interrupt CONT → A IOCR → A R2+A → R2, Bits 8~9 of R2 unchanged A→ R 0→A 0→R R-A → A R-A → R R-1 → A R-1 → R A ∨ VR → A A ∨ VR → R A&R→A A&R→R A⊕ R → A A⊕ R → R A+R→A A+R→R R→A R→R /R → A /R → R R+1 → A R+1 → R R-1 → A, skip if zero R-1 → R, skip if zero R(n) → A(n-1), R(0) → C, C → A(7) R(n) → R(n-1), R(0) → C, C → R(7) R(n) → A(n+1), R(7) → C, C → A(0) R(n) → R(n+1), R(7) → C, C → R(0) R(0-3) → A(4-7), R(4-7) → A(0-3) 45 STATUS AFFECTED None C None T,P T,P None <Note1> None None None None None None <Note1> Z,C,DC None Z Z Z,C,DC Z,C,DC Z Z Z Z Z Z Z Z Z,C,DC Z,C,DC Z Z Z Z Z Z None None C C C C None 2002/03/01 EM78P451 OTP ROM HEX 07rr 07rr 07rr 0xxx 0xxx 0xxx 0xxx MNEMONIC SWAP R JZA R JZ R BC R,b BS R,b JBC R,b JBS R,b 1 00kk kkkk kkkk 1kkk CALL k 1 1 1 1 1 1 1 1 1 1kkk 18kk 19kk 1Akk 1Bkk 1Ckk 1Dkk 1E02 1Fkk JMP k MOV A,k OR A,k AND A,k XOR A,k RETL k SUB A,k INT ADD A,k 0 0 0 0 0 0 0 INSTRUCTION BINARY 0111 01rr rrrr 0111 10rr rrrr 0111 11rr rrrr 100b bbrr rrrr 101b bbrr rrrr 110b bbrr rrrr 111b bbrr rrrr 01kk 1000 1001 1010 1011 1100 1101 1110 1111 kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk kkkk 0000 0010 kkkk kkkk OPERATION R(0-3) ↔ R(4-7) R+1 → A, skip if zero R+1 → R, skip if zero 0 → R(b) 1 → R(b) if R(b)=0, skip if R(b)=1, skip PC+1 → [SP], (Page, k) → PC (Page, k) → PC k→A A∨ k→ A A&k→A A⊕ k→ A k → A, [Top of Stack] → PC k-A → A PC+1 → [SP], 002H → PC k+A → A STATUS AFFECTED None None None None <Note2> None <Note3> None None None None None Z Z Z None Z,C,DC None Z,C,DC <Note1> This instruction is applicable to IOC5 ~ IOC9, IOCD~IOCF only. <Note2> This instruction is not recommended for RF operation. <Note3> This instruction cannot operate on R3F. This specification is subject to change without prior notice. 46 2002/03/01 EM78P451 OTP ROM 4.12 Timing Diagrams AC Test Input/Output Waveform 2.4 2.0 2.0 TEST POINTS 0.8 0.8 0.4 AC Testing : Input is driven at 2.4V for logic "1",and 0.4V for logic "0".Timing measurements are made at 2.0V for logic "1",and 0.8V for logic "0". RESET Timing (CLK="0") NOP Instruction 1 Executed CLK /RESET Tdrh TCC Input Timing (CLKS="0") Tins CLK TCC Ttcc This specification is subject to change without prior notice. 47 2002/03/01 EM78P451 OTP ROM 5. ABSOLUTE MAXIMUM RATING Items Temperature under bias Storage temperature Input voltage Output voltage Operating Frequency (2clk) Rating to to to to to 0°C -65°C -0.3V -0.3V DC This specification is subject to change without prior notice. 48 70°C 150°C +6.0V +6.0V 20MHz 2002/03/01 EM78P451 OTP ROM 6. ELECTRICAL CHARACTERISTICS (1) DC Characteristic (Ta=0°C~70°C, VDD=5V±5%, VSS=0V) Symbol FXT FRC IIL VIH1 VIL1 VIHX1 VILX1 VIH2 VIL2 VIHX2 VILX2 VOH1 VOH2 VOH3 VOL1 VOL2 VOL3 Parameter XTAL VDD to 2.3V XTAL VDD to 3V XTAL VDD to 5V RC VDD to 2.3V RC VDD to 3V RC VDD to 5V Input Leakage Current Input High Voltage VDD=5V) Input Low Voltage (VDD=5V) Clock Input High Voltage (VDD=5V) Clock Input Low Voltage (VDD=5V) Input High Voltage(VDD=3V) Input Low Voltage (VDD=3V) Clock Input High Voltage (VDD=3V) Clock Input Low Voltage (VDD=3V) Output High Voltage (Ports 5,6,8, P74~P77, P90~P92,P95~P97,and PF5~PF7) Output High Voltage (P70~P72) Output High Voltage (P93/SDO,P94/SCK) Output Low Voltage (Ports 5,6,8, P74~P77, P90~P92,P95~P97,and PF5~PF7)) Condition Two clocks Two clocks Typ VIN = VDD, VSS Max 4 8 20 4 4 4 ±1 2.0 0.8 OSCI 2.5 S7=1(IOCD Register bit7), IOH = -7.0mA S7=0(IOCD Register bit7), IOH = -7.0mA IOH = -5.0mA 0.4 V 2.4 Output Low Voltage (P93/SDO, P94/SCK) IOL = 7.0mA 49 V V 2.4 V 2.4 2.4 V IOL = 5.0mA S7=1(IOCD Register bit7), IOH = 10.0mA S7=0(IOCD Register bit7), IOH = 10.0mA µA V V V V 0.6 2 MHz V 1.5 OSCI IOH = -8.0mA MHz 1.0 1.5 OSCI Unit V OSCI Output Low Voltage (P70~P72) This specification is subject to change without prior notice. Min DC DC DC DC DC DC 0.4 0.4 V 0.8 V 0.4 0.4 V 2002/03/01 EM78P451 OTP ROM VOL4 IPH IPH2 Output Low Voltage (P74~P77) Pull-high current Pull-high current (P74,P75) ISB Power down current ICC Operating supply current IOL = 15.0mA Pull-high active, input pin at VSS 0.4 -50 Pull-high active, input pin at VSS -100 -240 1 µA mA All input and I/O pin at VDD, output pin floating, WDT enabled /RESET="High", Fosc=1.84324MHz (CK2="0"), output pin floating 10 µA 3 mA (2) AC Characteristic (Ta=0°C~70°C, VDD=5V±5%, VSS=0V) Symbol Dclk Tins Ttcc Twdt Tdrh Parameter Input CLK duty cycle Instruction cycle time (CK2="0") TCC input period Watchdog timer period Device reset hold period Conditions Min 45 RC Type 500 Typ 50 (Tins+20)/N* Ta=25°C Ta=25°C 18 181 Max 55 Unit % DC ns ns ms ms N= selected prescaler ratio. 1 NOTE: Vdd = 5V, set up time period = 16.2ms ± 5% Vdd = 3V, set up time period = 18.0ms ± 5% This specification is subject to change without prior notice. 50 2002/03/01 EM78P451 OTP ROM 7. Application Circuit EM78P451 This specification is subject to change without prior notice. 51 2002/03/01 EM78P451 OTP ROM APPENDIX Package Types: OTP MCU EM78P451P EM78P451AQ Package Type DIP QFP This specification is subject to change without prior notice. Pin Count 40 44 52 Package Size 600 mil 2002/03/01