Nexus3/ Module
e200z3 Power Architecture Core Reference Manual, Rev. 2
Freescale Semiconductor
10-5
Figure 10-2. Functional Block Diagram
10.2
Enabling Nexus3 Operation
The Nexus module is enabled by loading a single instruction, NEXUS3-Access, into the JTAG instruction
register/OnCE OCMD register. For the e200z3 Nexus3 module, the OCMD value is 0b00_0111_1100.
Once enabled, the module is ready to accept control input through the JTAG/OnCE pins.
The Nexus module is disabled when the JTAG state machine reaches the test-logic-reset state. This state
can be reached by the assertion of the j_trst_b pin or by cycling through the state machine using the j_tms
pin. The Nexus module can also be disabled if a power-on reset (POR) event occurs. If the Nexus3 module
nex_mseo0_b
nex_mcko
Ze
n V
irt
ua
l B
us
A
H
B S
ys
tem
Bu
s
Block
Nexus1 Block (w/in Zen CPU)
I/
O
L
o
gi
c
OnCE Debug
breakpoint /
Watchpoint
control
DM
A (
R
ea
d/
W
ri
te
)
In
st
ruc
ti
on
S
no
op
nex_mdo(N:0)
j_tdo
j_tdi
j_tms
j_tclk
j_trst_b
nex_evto_b
nex_rdy_b
nex_evti_b
DMA registers
control/status
registers
Registers
Message
Queues
Memory
Control
nex_mseo1_b
N+1
nex_aux_req(1:0)
npc_aux_grant
2
Note: The “nex_aux_req[1:0]”, “npc_aux_grant” & “nex_aux_busy” signals are used for inter-module
nex_aux_busy
communication in a multi-Nexus environment. They are not pins on the SoC.
ext_multi_nex_sel