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Rev.3.01
REJ03B0158-0301
Aug 08, 2007
Page 132 of 134
38D5 Group
Notes on QzROM Version
Wiring to OSCSEL pin
(1) OSCSEL = L
Connect the OSCSEL pin the shortest possible to the GND
pattern which is supplied to the V
SS
pin of the microcomputer. In
addition connecting an approximately 5 k
resistor in series to
the GND could improve noise immunity. In this case as well as
the above mention, connect the pin the shortest possible to the
GND pattern which is supplied to the V
SS
pin of the
microcomputer.
(2) OSCSEL = H
Connect the OSCSEL pin the shortest possible to the V
CC
pattern
which is supplied to the V
CC
pin of the microcomputer. In
addition connecting an approximately 5 k
resistor in series to
the V
CC
could improve noise immunity. In this case as well as
the above mention, connect the pin the shortest possible to the
V
CC
pattern which is supplied to the V
CC
pin of the
microcomputer.
<Reason>
The OSCSEL pin is the power source input pin for the built-in
QzROM.
When programming in the QzROM, the impedance of the
OSCSEL pin is low to allow the electric current for writing to
flow into the built-in QzROM. Because of this, noise can enter
easily. If noise enters the OSCSEL pin, abnormal instruction
codes or data are read from the QzROM, which may cause a
program runaway.
Fig. 107 Wiring for OSCSEL pin
Overvoltage in QzROM Version
Make sure that voltage exceeding the V
CC
pin voltage is not
applied to other pins. In particular, ensure that the state indicated
by bold lines in figure below does not occur for pin OSCSEL pin
(V
PP
power source pin for QzROM) during power-on or power-
off. Otherwise the contents of QzROM could be rewritten.
Fig. 108 Timing Diagram (Bold-lined periods are applicable)
QzROM Version Product Shipped in Blank
As for the product shipped in blank, Renesas does not perform
the writing test to user ROM area after the assembly process
though the QzROM writing test is performed enough before the
assembly process. Therefore, a writing error of approximate
0.1% may occur.
Moreover, please note the contact of cables and foreign bodies on
a socket, etc. because a writing environment may cause some
writing errors.
Ordering QzROM Writing
1. Notes On QzROM Writing Orders
When ordering the QzROM product shipped after writing,
submit the mask file (extension: .msk) which is made by the
mask file converter MM.
Be sure to set the ROM option (“MASK option” written in the
mask file converter) setup when making the mask file by using
the mask file converter MM.
2. ROM Code Protect
(QzROM Product Shipped After Writing)
As for the QzROM product shipped after writing, the ROM code
protect is specified according to the ROM option setup data in
the mask file which is submitted at ordering.
The ROM option setup data in the mask file is “00
16
” for protect
enabled, “FE
16
” (protect enabled to the protect area 1 only) or
“FF
16
” for protect disabled. Therefore, the contents of the ROM
code protect address (the reserved ROM area) of the QzROM
product shipped after writing is “00
16
”, “FE
16
” or “FF
16
”.
Note that the mask file which has nothing at the ROM option
data or has the data other than “00
16
”, “FE
16
” and “FF
16
” can not
be accepted.
3. Data Required for QzROM Ordering
The following are necessary when ordering a QzROM product
shipped after writing:
QzROM Writing Confirmation Form*
Mark Specification Form*
ROM data: Mask file
* For the QzROM writing confirmation form and the mark
specification form, refer to the “Renesas Technology Corp.”
Homepage (http://www.renesas.com/homepage.jsp).
Note that we cannot deal with special font marking (customer's
trademark etc.) in QzROM microcomputer.
OSCSEL
V
SS
The shortest
The shortest
about 5 k
Termination of OSCSEL pin
OSCSEL
V
CC
The shortest
The shortest
about 5 k
(1) OSCSEL = L
(2) OSCSEL = H
(1)
(1)
(1)
(1)
Note 1: It shows the microcomputer’s pin
V
CC
pin voltage
OSCSEL pin voltage
OSCSEL pin voltage
“L” input
1.8V
1.8V
(1) Input voltage to other MCU pins rises before V
CC
pin voltage.
(2) Input voltage to other MCU pins falls after V
CC
pin voltage.
Note: The internal circuitry is unstable when V
CC
is below the minimum voltage
specification of 1.8 V (shaded portion), so particular care should be
exercised regarding overvoltage.
(1)
(2)
~
~
~