2.5
Resets
The N1 SDP provides reset signals for the N1 board and N1 SoC.
N1 board resets
The N1 board has the following resets.
Table 2-4 N1 board resets
Reset
Source
Target
Comment
nPBRESET
Powerup reset.
Hardware reset user
push button
PBRESET.
Motherboard Configuration
Controller
(MCC) and entire
board
Main board powerup reset and hard reset from the user
hardware reset push button. The entire system goes to
standby state.
UART0_DSR
External device
MCC and entire board
Remote UART reset.
Must be enabled by use of configuration switch SW1. See
2.11.5 Push buttons and switches
CB_CFGnRST
MCC
Platform Controller Chip
(PCC) and entire board
The MCC controls the PCC reset.
IOFPGA_nPOR
MCC
IOFPGA, powerup reset
sections.
Enables the IOFPGA internal PLLs to be reset and become
stable before release of logic reset.
IOFPGA_nRST
MCC
IOFPGA logic, internal
blocks.
Resets main IOFPGA logic blocks.
nPBON
On/Off/Soft reset user
push button PBON
MCC and PCC
Push button to power up. By default, this button powers up
the system in standby mode.
nPBON
generates an interrupt
to either the MCC or PCC to control the powerup sequence.
N1 SoC resets
The N1 SoC has the following resets from the board.
Table 2-5 N1 SoC resets
Reset
Source
Comment
SOC_nPOR
MCC, IOFPGA.
Main powerup reset for the whole system except some SCC logic. De
‑
assertion of this
input initiates the powerup sequence.
SOC_nSRST
MCC/IOFPGA/external
debug unit.
Debug through reset signal. This signal enables the debug tools to debug Cortex
‑
M7
(SCP, MCP) and the N1 (AP) before the processors leave reset.
nTRST
External debug unit
JTAG reset. Resets the CoreSight DAP.
CFG_nRST
MCC through IOFPGA
Reset signal for the serial interface to the
System Configuration Controller
(SCC).
Reset sequence
The system can operate in two modes:
• Mobile mode:
— The board and SCP are brought up by the MCC alone.
• Enterprise mode:
— The MCC brings the board up to standby state and is then under the control of the PCC.
The following figure shows the board and SoC reset sequence.
2 Hardware description
2.5 Resets
101489_0000_02_en
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