82 www.ubicom.com IP2022 Data Sheet 6.0 In-System Programming The interface used for in-system programming (ISP) and
in-system  debugging  (ISD)  is  compatible  with  the  SPI
serial interface protocol. Whenever possible, a standard
connector should be incorporated in the system design for
in-system debugging and programming.                                                                                                                     The
recommended connector layout for the ISD/ISP interface
is shown in Figure 6-1. The connector is a male 10-pin
connector     with     100-mil     pin     spacing,     whose     pin
assignments  are  listed  in  Table  6-1.  The  connector  is
keyed to prevent backward insertion. Figure 6-1  ISD/ISP Connector Signal  levels  on  the  connector  are  LVTTL-compatible.
The  target  system  provides  the  TSCK,  TSI,  TRST,  and
TSS signals with 10K ohm pullup resistors. For more information about the ISD/ISP interface and the
interaction  between  the  debugger/programmer  and  the
target system, see the IP2022 User’s Manual. Table 6-1  Connector Pin Assignments Pin Name Description 1 KEY Key (not a signal) 2 TSS Target Slave Select—Active-low sig- nal which enables the IP2022 to com-
municate on the SPI bus. Connect to
pin 1 on the IP2022. 3 IOVss Ground 1 515-053.eps 3 5 7 9 2 4 6 8 10 4 TSCK Target Data Clock—Serial clock. Con- nect to pin 2 on the IP2022. 5 OSC Target Clock Oscillator—If the debug- ger/programmer is capable of supply-
ing an OSC clock for the target
system, then this clock must be con-
figurable so that it can be disabled to
prevent it from interfering with the tar-
get system (i.e. the OSC clock output
is placed in a high-impedance state). 6 Reserved Reserved 7 TRST Target Reset—The target system may use the TRST signal to reset the
entire system, to reset only the
IP2022, or it may ignore the TRST sig-
nal. The debugger/programmer may
provide a 100-ms system reset signal
(TRST) to the target system. If sup-
ported, the TRST output must be an
open-collector driver to accommo-
date other sources of reset in the tar-
get system. The minimum source
requirement for this driver is 6 mA.
The debugger/programmer should not
detect or be reset by the TRST signal
being driven low by the target system.
There is no requirement that the
IP2022 is connected to the TRST sig-
nal, so the debugger/programmer
cannot assume that the IP2022 has
been reset if the target system pulls
the TRST pin low. 8 TSI Target Serial Input—Sampled on the rising edge of TSCK. Connect to pin 3
on the IP2022. 9 IOVdd Power 10 TSO Target Serial Output—Driven by the IP2022 after the falling edge of
TSCK. Connect to pin 4 on the
IP2022.     Table 6-1  Connector Pin Assignments (continued)
Pin Name Description