Functional Description
The one clock cycle is 20ns, which corresponds to 50-MHz frequency.
•
Device detection
There is no specific identification routine executed prior to booting from an XIP device.
26.1.7.2.2 Pins Used
The list of device pins that are configured by the ROM in the case of NOR boot mode are as follows.
Please note that all the pins might not be driven at boot time. The decision as to which pins need to be
driven is done based on the type of NOR flash selected. The pins that are not listed below are not
configured by the ROM code and are left at power-on defaults. Specifically, external logic is needed to
isolate the upper address lines (A12–A27) of the NOR flash from the device pins and drive them low
during non-muxed NOR boot. Similarly for Muxed NOR Boot, address lines A16 and above to the memory
are not controlled by the ROM and need to be managed externally during boot to ensure proper
addressing to the all memory signals.
Once the initial software starts running, it can appropriately configure the pinmux setting for the lines and
remove the isolation to allow GPMC to drive all the address lines.
Table 26-9. Pins Used for Non-Muxed NOR Boot
Signal name
Pin used in XIP_MUX1
(1)
mode
Pin used in XIP_MUX2
(1)
mode
CS0
GPMC_CSN0
GPMC_CSN0
ADVN_ALE
GPMC_ADVN_ALE
GPMC_ADVN_ALE
OEN_REN
GPMC_OEN_REN
GPMC_OEN_REN
BE0N_CLE
GPMC_BEN0_CLE
GPMC_BEN0_CLE
WEN
GPMC_WEN
GPMC_WEN
WAIT
GPMC_WAIT0
GPMC_WAIT0
AD0 - AD15
GPMC_AD0 - GPMC_AD15
GPMC_AD0 - GPMC_AD15
A0
GPMC_A0
LCD_DATA0
A1
GPMC_A1
LCD_DATA1
A2
GPMC_A2
LCD_DATA2
A3
GPMC_A3
LCD_DATA3
A4
GPMC_A4
LCD_DATA4
A5
GPMC_A5
LCD_DATA5
A6
GPMC_A6
LCD_DATA6
A7
GPMC_A7
LCD_DATA7
A8
GPMC_A8
LCD_VSYNC
A9
GPMC_A9
LCD_HSYNC
A10
GPMC_A10
LCD_PCLK
A11
GPMC_A11
LCD_AC_BIAS_EN
(1)
XIP_MUX1 and XIP_MUX2 do not correspond to the pin mux modes that are defined for each terminal. This table identifies
which pins are used in each boot mode.
Table 26-10. Pins Used for Muxed NOR Boot
Signal name
Pin used in XIP_MUX1
(1)
mode
Pin used in XIP_MUX2
(1)
mode
CS0
GPMC_CSN0
GPMC_CSN0
ADVN_ALE
GPMC_ADVN_ALE
GPMC_ADVN_ALE
OEN_REN
GPMC_OEN_REN
GPMC_OEN_REN
BE0N_CLE
GPMC_BEN0_CLE
GPMC_BEN0_CLE
WEN
GPMC_WEN
GPMC_WEN
WAIT
GPMC_WAIT0
GPMC_WAIT0
AD0 - AD15
GPMC_AD0 - GPMC_AD15
GPMC_AD0 - GPMC_AD15
(1)
XIP_MUX1 and XIP_MUX2 do not correspond to the pin mux modes that are defined for each terminal. This table identifies
which pins are used in each boot mode.
4117
SPRUH73H – October 2011 – Revised April 2013
Initialization
Copyright © 2011–2013, Texas Instruments Incorporated