Chapter 9 Test Function; Test Pins; Test Bus Pins (Tbi39 To Tbi0 And Tbo34 To Tbo0); Bunri And Test Pins - Renesas NU85E Preliminary User's Manual

The NU85E is equipped with an on-chip test interface control unit (TIC) for testing the NU85E itself or connected
peripheral macros via the test buses (TBI39 to TBI0 and TBO34 to TBO0). The test buses are effective when the
TEST and BUNRI signals are active.

9.1 Test Pins

9.1.1 Test bus pins (TBI39 to TBI0 and TBO34 to TBO0)

The test bus pins are used in place of normal pins when the NU85E is in unit test mode.
Always extend these pins outside of the ASIC (they can be used in combination with normal pins).
For details, refer to the various cell-based IC family design manuals.

9.1.2 BUNRI and TEST pins

These pins are used to select normal, unit test, or standby test mode.
BUNRI Pin Input Level
Low level
High level
High level
(1) Normal mode
This is the mode the user normally uses.
When a low-level signal is being input to the BUNRI pin, the pins other than the test pins are enabled, and the
NU85E is in normal mode. At this time, input to the TBI39 to TBI0 pins is ignored, and the TBO34 to TBO0 pins
are set to high impedance.
(2) Unit test mode and standby test mode
When a high-level signal is being input to the BUNRI pin, the NU85E is in test mode. The two types of test mode
are unit test mode and standby test mode.
Circuits should be designed so that floating or bus contention does not occur for the pins constituting the bus
(excluding test pins) during unit or standby test mode (For the pin status in each mode, see 2.4 Pin Status).
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CHAPTER 9 TEST FUNCTION

Table 9-1. List of Test Mode Settings
TEST Pin Input Level
Arbitrary
Low level
High level
Preliminary User's Manual A14874EJ3V0UM
Mode
Normal mode
Standby test mode
Unit test mode