IBM EM78P447N 5 R4 RAM Select Register, 6 R5~R7 Port 5 ~ Port7, R5, R6 and R7 are I/O registers

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EM78P447N

8-Bit Microcontroller with OTP ROM

4.1.4	R3 (Status Register)

7			6		5			4		3		2		1		0
GP			PS1		PS0			T		P		Z		DC		C

Bit 7 (GP) General read/write bit.

Bits 6 (PS1) ~ 5 (PS0) Page select bits. PS1~PS0 are used to pre-select a program memory page. When executing a "JMP", "CALL", or other instructions which causes the program counter to change (e.g. MOV R2, A), PS1~PS0 are loaded into the 11th and 12th bits of the program counter and select 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 PS1~PS0 bits current setting.

PS1		PS0		Program memory page [Address]

0		0		Page 0 [000-3FF]
0		1		Page 1 [400-7FF]
1		0		Page 2 [800-BFF]
1		1		Page 3 [C00-FFF]

Bit 4 (T)		Time-out bit. Set to 1 with the "SLEP" and "WDTC" commands, or during
		power up, and reset to 0 with the WDT time-out.
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 2	(Z)	Zero flag. Set to "1" if the result of an arithmetic or logic operation is zero.
Bit 1	(DC) Auxiliary carry flag.
Bit 0	(C)	Carry flag

4.1.5 R4 (RAM Select Register)

Bits 7~6 determine which bank is activated among the 4 banks.

Bits 5~0 are used to select the registers (address: 00~3F) in the indirect addressing mode.

If no indirect addressing is used, the RSR can be used as an 8-bit general-purpose read/writer register.

See the configuration of the data memory in Fig. 4.

4.1.6 R5~R7 (Port 5 ~ Port7)

R5, R6 and R7 are I/O registers

4.1.7 R8~R1F and R20~R3E (General Purpose Register)

R8~R1F, and R20~R3E (including Banks 0~3) are general-purpose registers.

10 •	Product Specification (V1.1) 03.30.2005

(This specification is subject to change without further notice)

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Contents EM78P447N Elan Microelectronics Corporation Contents Specification Revision History General Description EM78P447NBWM PIN Assignment EM78P447NAS Pin Description Symbol Pin No Type FunctionEM78P447NAP and EM78P447NAM Pin Description EM78P447NCK and EN78P447NCM Pin Description Power supplyEM78P447NBP and EM78P447NBWM Pin Description Function Description EM78P447NDK and EM78P447NDM Pin Description2 R1 Time Clock /Counter Operational Registers1 R0 Indirect Addressing Register 3 R2 Program Counter & StackCall RET Retl Reti FffhData Memory Configuration 7 R8~R1F and R20~R3E General Purpose Register 5 R4 RAM Select Register6 R5~R7 Port 5 ~ Port7 R5, R6 and R7 are I/O registersAccumulator Special Purpose Registers8 R3F Interrupt Status Register Control RegisterTCC Rate 3 IOC5 ~ IOC7 I/O Port Control RegisterIocb Wake-up Control Register for Port6 WDT RateIoce WDT Control Register WUEIocf Interrupt Mask Register ExieTCC and WDT Block Diagram TCC/WDT & PrescalerI/O Ports IODReset and Wake-up ResetUsage of Sleep1 and Sleep2 Mode SLEEP2 SLEEP1Address Name Reset Type Bit Summary of the Initialized Values for RegistersWUE7 WUE6 WUE5 WUE4 R3FISRExif Tcif IocbStatus of RST, T, and P of Status Register Previous status before resetPrevious value before reset Events that may Affect the T and P StatusController Reset Block Diagram InterruptMode OscillatorOscillator Modes Conditions Crystal Oscillator/Ceramic ResonatorsXTALSummary of Maximum Operating Speeds Fxt max.MHzHXT External RC Oscillator ModeOscillator Type Frequency Mode C1pF C2pF LXTCode Option Register Code Option Register WordPR2~PR0 are protect bits, protect type as following ProtectCustomer ID Register Word Power On ConsiderationsExternal Power On Reset Circuit Bit 12~0 Customer’s ID codeReset Residue-Voltage ProtectionInstruction Set Contw NOPDAA SlepRrca R Djza RDJZ R RRC RTiming Diagram AC Test Input/Output W aveformTa= 25 C, VDD= 5.0V±5%, VSS= DC Electrical CharacteristicSymbol Parameter Condition Min Typ Max Unit Items RatingTa=- -40 C ~ 85 C, VDD=5V ±5%, VSS=0V AC Electrical CharacteristicSymbol Parameter Conditions Min Typ Max Unit Device characteristic Vih, Vil of TCC, /INT, /RESET PinPort5, Port6 Port7 Voh vs. Ioh,VDD=5V Port5, Port6, and Port7 Voh vs. Ioh, VDD=3V Vol/Iol VDD=5V Vol/Iol VDD=3V Vol/Iol 100 Vol/Iol WDT Cext=100pF, Typical RC OSC Frequency Typical ICC1 and ICC2 vs. Temperature Maximum ICC1 and ICC2 vs. Temperature Typical ISB1 and ISB2 vs. Temperature Maximum ISB1 and ISB2 vs. Temperature EM78P447N HXT ImA Lead plastic dual inline package（DIP）－ 300 mil Package Type Pin Count Package SizeLead plastic dual inline skinny package（DIP）－ 300 mil Lead plastic dual inline package（DIP）－ 600 mil838 27TYP EM78P447N