EF6805P2 datasheet(10/31 Pages) STMICROELECTRONICS

Part #	EF6805P2

Description	8-BIT MICROCOMPUTER UNIT

PDF	31 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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10 / 31 page

The A and X registers and all RAM locations except

$07F and $07E are modified.

ROM CHECKSUM SUBROUTINE - The ROM self-

check is called at location $F95. The A register

should be cleared before calling the routine. If any

error is detected, it returns with the Z bit cleared ;

otherwise Z = 1, X = 0 on return, and A is zero if the

test passes. RAM location $040 to $043 is overwrit-

ten. The checksum is the complement of the execu-

tion OR of the contents of the user ROM.

* This connection depends on clock oscillator user selectable

mask option. Use jumper if the RC mask option is selected.

Figure 11 : Self-check Connections.

LED MEANINGS

PC0 PC1 PC2 PC3

Remarks

(1 : LED ON ; 0 : LED OFF)

Bad I/O

Bad Timer

Bad RAM

Bad ROM

Bad Interrupts or Request Flag

All Flashing

Good Device

EF6805U3

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EF6805P2 Datasheet(PDF) 10 Page - STMicroelectronics