![NXP Semiconductors LPC43Sxx Скачать руководство пользователя страница 616](http://html1.mh-extra.com/html/nxp-semiconductors/lpc43sxx/lpc43sxx_user-manual_1721827616.webp)
UM10503
All information provided in this document is subject to legal disclaimers.
© NXP B.V. 2015. All rights reserved.
User manual
Rev. 2.1 — 10 December 2015
616 of 1441
NXP Semiconductors
UM10503
Chapter 23: LPC43xx/LPC43Sxx External Memory Controller (EMC)
23.7.22 Static Memory Write Enable Delay registers
These registers enable you to program the delay from the chip select to the write enable.
It is recommended that these registers are modified during system initialization, or when
there are no current or outstanding transactions. This can be ensured by waiting until the
EMC is idle, and then entering low-power, or disabled mode. These registers are
accessed with one wait state.
23.7.23 Static Memory Output Enable Delay registers
These registers enable you to program the delay from the chip select or address change,
whichever is later, to the output enable. It is recommended that these registers are
modified during system initialization, or when there are no current or outstanding
transactions. This can be ensured by waiting until the EMC is idle, and then entering
low-power, or disabled mode. These registers are accessed with one wait state.
23.7.24 Static Memory Read Delay registers
These registers enable you to program the delay from the chip select to the read access.
It is recommended that these registers are modified during system initialization, or when
there are no current or outstanding transactions. This can be ensured by waiting until the
EMC is idle, and then entering low-power, or disabled mode. It is not used if the extended
wait bit is enabled in the StaticConfig registers. These registers are accessed with one
wait state.
Table 437. Static Memory Write Enable Delay registers (STATICWAITWEN[0:3], address
0x4000 5204 (STATICWAITWEN0) to 0x4000 5264 (STATICWAITWEN3)) bit
description
Bit
Symbol
Description
Reset
value
3:0
WAITWEN
Wait write enable.
Delay from chip select assertion to write enable.
0x0 = One EMC_CCLK cycle delay between assertion of chip select
and write enable (POR reset value).
0x1 - 0xF = (n + 1) EMC_CCLK cycle delay. The delay is (WAITWEN
+1) x tEMC_CCLK.
0x0
31:4
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
-
Table 438. Static Memory Output Enable delay registers (STATICWAITOEN[0:3], address
0x4000 5208 (STATICWAITOEN0) to 0x4000 5268 (STATICWAITOEN3)) bit
description
Bit
Symbol
Description
Reset
value
3:0
WAITOEN
Wait output enable.
Delay from chip select assertion to output enable.
0x0 = No delay (POR reset value).
0x1 - 0xF = n cycle delay. The delay is WAITOEN x tEMC_CCLK.
0x0
31:4
-
Reserved, user software should not write ones to reserved bits. The
value read from a reserved bit is not defined.
-