NXP Semiconductors LPC24XX UM10237 - Manual (Page 38)

UM10237_4 © NXP B.V. 2009. All rights reserved.
User manual Rev. 04 — 26 August 2009 38 of 792
NXP Semiconductors
UM10237
Chapter 3: LPC24XX System control
3.3.2.1 Examples of AHB2 settings
[1] Sequence based on round-robin.
3.4 Other system controls and status flags
Some aspects of controlling LPC2400 operation that do not fit into peripheral or other
registers are grouped here.
3.4.1 System Controls and Status register (SCS - 0xE01F C1A0)
Table 36. Priority sequence (bit 0 = 0): Ethernet, CPU
Bit Symbol Description Priority value nn Priority sequence
13:12 EP1 CPU 10 (2) 1
17:16 EP2 Ethernet 01 (1) 2
Table 37. Priority sequence (bit 0 = 0): Ethernet, CPU
Bit Symbol Description Priority value nn Priority sequence
13:12 EP1 CPU 00 2 [1]
17:16 EP2 Ethernet 00 1 [1]
Table 38. System Controls and Status register (SCS - address 0xE01F C1A0) bit description
Bit Symbol Value Description Access Reset
value
0 GPIOM GPIO access mode selection. R/W 0
0 GPIO ports 0 and 1 are accessed via APB addresses in a fashion
compatible with previous LPC2000 devices.
1 High speed GPIO is enabled on ports 0 and 1, accessed via addresses in
the on-chip memory range. This mode includes the port masking feature
described in the GPIO chapter.
1 EMC Reset
Disable
[1]
External Memory Controller Reset Disable. R/W 0
0 Both EMC resets are asserted when any type of reset event occurs. In this
mode, all registers and functions of the EMC are initialized upon any reset
condition.
1 Many portions of the EMC are only reset by a power-on or brown-out event,
in order to allow the EMC to retain its state through a warm reset (external
reset or watchdog reset). If the EMC is configured correctly, auto-refresh can
be maintained through a warm reset.
2 EMC Burst
Control External Memory Controller burst control (implemented on device revisions
C and higher). R/W 0
0 Burst enabled.
1 Burst disabled.
3 MCIPWR
Active
Level
[1]
MCIPWR pin control. R/W 0
0 The MCIPWR pin is low.
1 The MCIPWR pin is high.
4 OSCRANGE Main oscillator range select. R/W 0
0 The frequency range of the main oscillator is 1 MHz to 20 MHz.
1 The frequency range of the main oscillator is 15 MHz to 25 MHz.