SH69P25/P23/P20B EVB
Application Note for SH69P25/P23/P20B EVB
SH69P25/P23/P20B EVB
The SH69P25/P23/P20B EVB is used to evaluate the SH69P25/P23/P20B chip's function for the development of application
program. It contains of a SH69V25 chip to evaluate the functions of SH69P25/P23/P20B. The following figure shows the
placement diagram of SH69P25/P23/P20B EVB.
J5J4
VCC GND
POWER
STOP HALT
ROMLROMH U4U5
U6
U7
S1
J6
5V 3V EXT
74HC273
74HC273
1ON2345678
J1
1
U2
74HC245 U3 74HC245
SH69V25
U1
J8
ICE
ST-AL
J2
1
R1
J7
X1
RC
OSC
J3
1
S2
RESET
Ver 1.1 1/7
SH69P25/P23/P20B EVB
There are two configurations of SH69P25/P23/P20B EVB in application development: ICE mode and stand-alone mode.
In the ICE mode, the SH66xx ICE (motherboard) is connected to the SH69P25/P23/P20B EVB by the ICE interface.
Power
User Application Board
Keyboard Array
SH69P25 Evaluation
Board
66 series RICE
PC
(a) ICE mode
In the standalone mode, the SH69P25/P23/P20B EVB is no longer connected to the motherboard. But the EPROM board has
must be connected to the SH69P25/P23/P20B EVB by the EPROM interface. The EPROMs which may be the 27512 or
27256 store the application program;.
Power
SH69P25 Evaluation
Board
User Application Board
Keyboard Array
(b) Stand-alone mode
The process of your program’s evaluation on SH69P25/P23/P20B EVB
Uasm66.exe: assemble the program, and get binary (*.obj) file and the other files.
Depart the one 16 bits obj file to the two 8 bits files by convert.exe.
Usage example (for example: aaa.asm):
1.Run the SH66 series assemble program:
C: >uasm66 aaa.asm ; to produce the obj file: aaa.obj
2. Depart the aaa.obj to two 8 bits files aaah.obj and aaal.obj, for example:
C: > convert
Input the 16 bits (.obj) file aaa.obj
Then aaah.obj and aaal.obj will be created.
3. Write the aaah.obj to EPROM (ROMH)
Write the aaal.obj to EPROM (ROML)
4. Put the two EPROMs (ROML and ROMH) on the EV board U4,U5.
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SH69P25/P23/P20B EVB
SH69P25/P23/P20B EVB Programming Notes:
1. Clear data RAM and initialize all system registers at the beginning.
2. Do not perform logical operation with I/O ports. Especially when the I/O ports have external connections.
3. Do not perform arithmetic operation with those registers only have 1, 2 or 3 bits. This kind of operation may not get the
result you expected.
4. Never use reserved registers.
5. If “IE” instruction (interrupt enable) is set outside the interrupt processing program and there is “HALT” or “STOP”
instruction, this two instructions should be followed “IE” instruction closely.
6. After CPU responding to an interrupt, IRQ should be cleared before resetting IE in order to avoid many responses to one
interrupt.
7. Interrupt Enable instruction will be automatically cleared after entering interrupt-processing program. If setting IE too
early, there is a possibility of re-entry the interrupt. So the Interrupt Enable instruction should be placed at the end and
followed closely by two instructions include “RTNI”.
8. During the two successive instruction cycles next to Interrupt Enable instruction, CPU will not respond to any interrupts.
9. After CPU responding to interrupts, each bit of IE will be cleared by hardware while IRQ should be cleared by software.
10. It is necessary to add NOP before or after the HALT instruction, else the CPU will execute error instruction when it
wakes up from the HALT.
.
. .
NOP
HALT
NOP
.
. .
11. It is wise to set Interrupt Enable flag before you return from subroutine in two instruction.
.
. .
LDI IE, 04H ; Enable timer0 interrupt
LDA Temp,0
RTNI
12. When you set Interrupt enable flag as the following and your subroutine do not set Interrupt Enable flag, then your
system will never wake up if an interrupt entered between the NOPs.
Sample: incorrect use!
. .
LDI IE, 1111B; IE = Interrupt enable flag
NOP
NOP
NOP
HALT
.
. .
13. To add “p=66xx” and “romsize=xxxx” at the beginning of a program. If any problem is found in compiling the program,
check if the SH6566.dev is located at the program directory.
14. When setting Timer Counter, first fill TOL, then TOH.
15. After setting TM0, TOL, TOH, it is unnecessary to reset them after interrupt each time. If TM0, TOL, TOH are reset after
each TIMER interrupt, interrupt interval time will not equal because the interrupt timing is not successive.
16. Any instruction containing writing to or reading from memory, it should not be used to operate with I/O Port. It is best to
avoid using those instructions such as “SUB, ADD “ which do not contain Write operation with I/O Port but have
computation operation.
17. When the internal pull-up resistor is on, “1” must be written to I/O Port before Reading. And when the internal pull-low
resistor is on, “0” must be written to I/O Port before Reading.
18. Directly reading PORT states ensure the count is correct.
19. Interrupt activating from STOP at the first time can save power.
20. When the Compiler of old version compiles program, the last line will be read twice. So, if the last line is an instruction,
two same operations will be occurred. If there is Label in the last line, compiler will give an error named ‘repeated
definition’. This will happen in main program or included files and it is recommended that the last line should be a blank
line or END.
21. The stack has four layers, if an interrupt is enabled, there only have three layers can be used. Otherwise, if an interrupt
comes, the stack will be overflowed that will cause CPU Reset or other errors.
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SH69P25/P23/P20B EVB
22. Key De-bounce time is recommended to be 50ms. If a user use Rubber Key, it is best to test Rubber Key’s De-bounce
time.
23. Index register DPH and DPM both have three bits only, so pay attention to the referred address when using them.
24. It takes about 0.3 second to wake up from STOP when using 32768Hz crystal. So, if the system is waked up by key
pressing, the key may have been released when the program begins to read Key value. Please pay more attention to
this problem.
25. The “NOP” instruction should be added at the beginning of the program to ensure the IC is stability.
26. When SH69P25/P23/P20B EVB is used to evaluate the SH69P23, $0B-$0C must be always kept as 00h and $19-$1A
must be always kept as 0Fh in user’s program.
27. SH69P25/P23/P20B EV board is designed for SH69P25, SH69P23 and SH69P20B.
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SH69P25/P23/P20B EVB
SH69P25/P23/P20B interface connector: J3 (TOP View from EVB)
PORTE[2]
PORTE[3]
PORTF[1]
PORTA[2]
PORTA[3]
T0
RESETB
GND
PORTB[0]
PORTB[1]
PORTB[2]
PORTB[3]
PORTD[0]
PORTD[1] PORTD[2]
1
PORTE[1]
PORTE[0]
PORTF[0]
PORTA[1]
PORTA[0]
EXOSC_IN
VDD_EXT
PORTC[3]
PORTC[2]
PORTC[1]
PORTC[0]
PORTD[3]
SH69P20B
interface
SH69P23
interface
SH69P25
interface
External Vcc input : J4,J5 (The external power input when the EV. Board worked in stand-alone mode.
The voltage of Vcc must be 5V±5%)
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SH69P25/P23/P20B EVB
Jumper setting:
J6 (EVB power select):
! Short the 5V positions, the voltage (5V) of SH69V25 is internal source.
! Short the 3V positions, the voltage (3V) of SH69V25 is internal source.
! Short the EXT positions, the external power (2.4~6.0V, refer to SH69P25 or SH69P23 or SH69P20B spec) of
SH69V25 is input from VDD PIN of J3 (J3/16).
J8 (SH69P25/P23/P20B EVB ICE/Stand-alone mode select):
! If you short the “ICE” position (only for ICE mode), the clock of SH69P25/P23/P20B EVB is fed from the ICE.
! If you short the “Stand alone” positions (only for stand-alone mode), the system clock is selected by S1(bit 6, 7, 8) and
J7.
Switch setting:
S1:
1. If you turn on bit 1 (STKOF) of this switch, then
2. If you turn on bit 2 (LVRV) of this switch, then select
Note: the low level LVR(2.5V) is not used for SH69P20B. (Please reference to the SH69P20B datasheet.)
3. If you turn on bit 3 (LVR) of this switch, then
4. If you turn on bit 4 (WDT) of this switch, then
function
5. If you turn on bit 5 (OSC3) of this switch, then select the high frequency clock; else select the low frequency clock.
6. OSC2, OSC1, OSC0:
S2:
Reset the whole system when push the button.
.
Off, off, off select external clock from OSCI;
On, off, off select RC oscillator;
On, on, off select 400K~4MHz Crystal or ceramic
On, on, on select 32.768K Crystal resonator;
enable the stack overflow
the low level LVR(2.5V)
enable the LVR
enalbe the Watch Dog function
function, else
resonator
function in ICE mode; else disable it.
, else select
disable the LVR
;
the high level LVR(4V)
function
disable the Watch Dog
, else
.
LED declare:
Power: Green LED is lighted when power of the EVB is on.
HALT: Yellow LED is lighted when the system has gone into the HALT mode
STOP: Red LED is lighted when the system has gone into the STOP mode
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SH69P25/P23/P20B EVB
Note:
Evaluate your program with ICE indicate:
1. After enter to RICE66 and successfully download the user program, push the F5 (Reset) on PC keyboard before run
your program when you evaluate your program with ICE. If there were abnormal response, the user should power off the
ICE, quit RICE66 and wait for a few seconds before restart.
2. First time run RICE66, need to select an appropriate MCU type, clock frequency ... save the settings and restart RICE66
again.
3. Can
4. When you want to escape from HALT or STOP (in ICE mode), you should press the F5 key on PC keyboard twice.
5. The maximum current limit of the 3V power is 100mA, when the user uses internal 3V power to drive external device
6. When EV. Board worked in “with ICE” mode, you can input the clock from EXOSC_IN (JP3/8) as the system clock.
’
t Step (F8) or Over (F9) a HALT and STOP instruction.
such as LED.
(refer to the RICE66 User’s Guide)
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