Section 25 User Debug Interface (H-UDI)
Rev. 3.00 Jan 25, 2006 page 758 of 872
REJ09B0286-0300
25.6
Usage Notes
1. A reset must always be executed by driving the
ETRST
pin to 0, regardless of whether or not
the H-UDI is to be activated. The
ETRST
pin must be held low for 20 ETCK clock cycles. For
details, see section 29, Electrical Characteristics. To activate the H-UDI after a reset, drive the
ETRST
pin to 1 and specify the ETCK, ETMS, and ETDI pins to any value. If the H-UDI is
not to be activated, drive the
ETRST
, ETCK, ETMS, and ETDI pins to 1 or the high-
impedance state. These pins are internally pulled up and are noted in standby mode.
2. The following must be considered when the power-on reset signal is applied to the
ETRST
pin.
The reset signal must be applied at power-on.
To prevent the LSI system operation from being affected by the
ETRST
pin of the board
tester, circuits must be separated .
Alternatively, to prevent the
ETRST
pin of the board tester from being affected by the LSI
system reset, circuits must be separated.
Figure 25.3 shows a design example of the reset signal circuit wherein no reset signal
interference occurs.
Power-on
reset circuit
Board edge pin
System reset
ETRST
RES
ETRST
This LSI
Figure 25.3 Reset Signal Circuit Without Reset Signal Interference
3. The registers are not initialized in standby mode. If the
ETRST
pin is set to 0 in standby mode,
IDCODE mode will be entered.
4. The frequency of the ETCK pin must be lower than that of the system clock. For details, see
section 29, Electrical Characteristics.
5. Data input/output in serial data transfer starts from the LSB. Figure 25.4 shows examples of
serial data input/output.
6. When data that exceeds the number of bits of the register connected between the ETDI and
ETDO pins is serially transferred, the serial data that exceeds the number of register bits and
output from the ETDO pin is the same as that input from the ETDI pin.
7. If the H-UDI serial transfer sequence is disrupted, the
ETRST
pin must be reset. Transfer
should then be retried, regardless of the transfer operation.
Summary of Contents for H8S/2158
Page 10: ...Rev 3 00 Jan 25 2006 page viii of lii...
Page 36: ...Rev 3 00 Jan 25 2006 page xxxiv of lii B Product Lineup 863 C Package Dimensions 864 Index 865...
Page 47: ...Rev 3 00 Jan 25 2006 page xlv of lii Appendix Figure C 1 Package Dimensions TBP 112A 864...
Page 54: ...Rev 3 00 Jan 25 2006 page lii of lii...
Page 70: ...Section 1 Overview Rev 3 00 Jan 25 2006 page 16 of 872 REJ09B0286 0300...
Page 118: ...Section 3 MCU Operating Modes Rev 3 00 Jan 25 2006 page 64 of 872 REJ09B0286 0300...
Page 126: ...Section 4 Exception Handling Rev 3 00 Jan 25 2006 page 72 of 872 REJ09B0286 0300...
Page 198: ...Section 6 Bus Controller Rev 3 00 Jan 25 2006 page 144 of 872 REJ09B0286 0300...
Page 326: ...Section 10 8 Bit PWM Timer PWM Rev 3 00 Jan 25 2006 page 272 of 872 REJ09B0286 0300...
Page 440: ...Section 15 Watchdog Timer WDT Rev 3 00 Jan 25 2006 page 386 of 872 REJ09B0286 0300...
Page 606: ...Section 17 I 2 C Bus Interface IIC Rev 3 00 Jan 25 2006 page 552 of 872 REJ09B0286 0300...
Page 742: ...Section 19 Multimedia Card Interface MCIF Rev 3 00 Jan 25 2006 page 688 of 872 REJ09B0286 0300...
Page 750: ...Section 21 D A Converter Rev 3 00 Jan 25 2006 page 696 of 872 REJ09B0286 0300...
Page 768: ...Section 22 A D Converter Rev 3 00 Jan 25 2006 page 714 of 872 REJ09B0286 0300...
Page 770: ...Section 23 RAM Rev 3 00 Jan 25 2006 page 716 of 872 REJ09B0286 0300...
Page 824: ...Section 26 Clock Pulse Generator Rev 3 00 Jan 25 2006 page 770 of 872 REJ09B0286 0300...
Page 844: ...Section 27 Power Down Modes Rev 3 00 Jan 25 2006 page 790 of 872 REJ09B0286 0300...
Page 878: ...Section 28 List of Registers Rev 3 00 Jan 25 2006 page 824 of 872 REJ09B0286 0300...
Page 926: ...Index Rev 3 00 Jan 25 2006 page 872 of 872 REJ09B0286 0300...