MPC5200B Users Guide, Rev. 1
21-4 Freescale Semiconductor
TLM and TAP Signal Descriptions
Figure 21-3. Generic Slave TAP
21.3 TLM and TAP Signal Descriptions

21.3.1 Test Reset ( TRST)

JTAG reset, active low. When asserted, any on-going JTAG operation is immediately aborted. All TAP state machines , including the TLM,
immediately enter the Test-Logic-Reset state. Other JTAG input signals (TCK, TMS, and TDI) have no effect while TRST is asserted. TDO
is immediately tri-stated.

21.3.2 Test Clock ( TCK)

This is the JTAG clock. The (non-reset) behavior of the active TAP and TLM state machines is governed by the TMS value at the TCK rising
edge. TDI value is sampled at the TCK rising edge for all shift operations. All TDO non-reset transitions (including impedance) occur at the
TCK falling edge. All shift register capture operations occur at the TCK rising edge. All shift register Update operations occur at the TCK
falling edge.

21.3.3 Test Mode Select ( TMS)

TAP state machine control, including TLM. The state of TMS at rising edges of TCK uniquely determines the state sequence of the TLM and
the active TAP state machines. See Figure21-4. Inactive TAPs ignore TMS completely.

21.3.4 Test Data In ( TDI)

Serial test data input can be routed to any IR or DR, as determined by the state of the active TAP state machine and the contents of the active
IR. TDI is sampled at the TCK rising edge while the active TAP state machine is in either the Shift-IR or Shift-DR state.
DeviceID
BdyScan
Bypass
ShiftDR
ClockDR
UpdateDR SEL
TDO
TDI
ENA
TMS
TCK
Update-DR or Run-Test/Idle
ShiftDR
ClockDR
UpdateDR
ShiftIR
ClockIR
UpdateIR
TAP State
TRST-
IR
edoce
Machine
1
0
&