MC68HC05P9A Datasheet, PDF (25/158 Pages) Freescale Semiconductor, Inc – HCMOS Microcontroller Unit

Freescale Semiconductor, Inc.
Memory
Self-Check Mode
Self-Check Mode
The self-check program resides at mask ROM locations $1F00 to
$1FEF. This program is designed to check the part’s functionality with a
minimum of support hardware. The COP subsystem is disabled in the
self-check mode so that routines that feed the COP do not exist in the
self-check program.
The self-check mode is entered on the rising edge of RESET if the IRQ
pin is driven to double the supply voltage and the TCAP/PD7 pin is at
logic 1. RESET must be held low for 4064 cycles after POR or for a time,
t_RL, for any other reset. After reset, the I/O, RAM, ROM, timer, and SIOP
are tested. Self-check results (using LEDs as monitors) are shown in
Table 3. It is not recommended that the user code use any of the
self-check code. The self-check code is subject to change at any time to
improve testability or manufacturability.
Table 3. Self-Check Results
PC2
PC1
PC0
Remarks
0
0
1
Bad I/O
0
1
0
Bad RAM
0
1
1
Bad Timer
1
0
0
Bad ROM
1
0
1
Bad Serial
Flashing
Good Device
All Others
Bad Device
0 indicates LED is on; 1 indicates LED is off.
11-mc68hc05p9a
MOTOROLA
Memory
25
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