![Marvell PXA300 Скачать руководство пользователя страница 134](http://html.mh-extra.com/html/marvell/pxa300/pxa300_developers-manual_1734615134.webp)
69rlq62d-f714peg4 * Memec (Headquar
ter
s) - Unique
Tec
h,
Insight,
Impact
MAR
VELL CONFIDENTIAL,
UNDER ND
A# 12101050
69rlq62d-f714peg4 * Memec (Headquar
ter
s) - Unique
Tec
h,
Insight,
Impact
MAR
VELL CONFIDENTIAL,
UNDER ND
A# 12101050
69r
lq62d-f714peg4 * Memec (Headquar
ters) - Unique
T
ech, Insight, Impact * UNDER ND
A# 12101050
MAR
VELL CONFIDENTIAL - UNA
UTHORIZED DISTRIB
UTION OR USE STRICTL
Y PR
OHIBITED
PXA300 Processor and PXA310 Processor
Vol. I: Timer and System Configuration Developers Manual
Doc. No. MV-TBD-00 Rev. A
CONFIDENTIAL
Copyright © 12/13/06 Marvell
Page 134
Document Classification: Proprietary Information
December 13, 2006
Not approved by Document Control. For review only.
5.3.8
GPIO Falling-Edge Detect-Enable Registers (GFERx)
Each GPIO can be programmed to detect a rising edge, falling edge, or either transition on a port. Refer to the
PXA300 Processor and PXA310 Processor Electrical, Mechanical, and Thermal Specification for the minimum
pulse width to guarantee a detection. When an edge is detected that matches the type of edge programmed for the
port, a status bit is set.
The GPIO Rising-Edge and Falling-Edge Detect-Enable registers (GRERx and GFERx, respectively) select the
type of transition on a GPIO port that causes a bit within the GPIO Edge-Detect Enable Status register (GEDRx)
to be set. For a given GPIO port, its corresponding GFERx bit is set to cause a GEDRx status bit to be set when
the port transitions from logic level high to logic level low. Likewise, GRERx is used to set the corresponding
GEDRx status bit when a transition from logic level low to logic level high occurs. When the corresponding bits
are set in both registers, either a falling- or a rising-edge transition causes the corresponding GEDRx status bit to
be set.
shows the falling-edge enable bit locations corresponding to all 32 ports of GFERx.
A pair of set/clear registers are also provided to enable the setting and clearing of individual bits of the GFERx
registers.
5.3.9
GPIO Bit-Wise Set Falling-Edge (GSFERx) and GPIO
Bit-wise Clear Falling-Edge (GCFERx) Detect-Enable
Registers
Users can directly change the programming of GFERx by writing to GSFERx and GCFERx.
Table 5-11. GFERx Bit Definitions
Physical Address
0x40E0_003C
0x40E0_0040
0x40E0_0044
0x40E0_013C
GFER0
GFER1
GFER2
GFER3
GPIO Controller
User
Settings
Bit
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9
8
7
6
5
4
3
2
1
0
FE[31:0]
Reset
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Bits
Access
Name
Description
n
R/W
FE{n}
GPIO port falling-edge detect enable n (where n = 0 through 31)
0 – Disable falling-edge detect enable
1 – Set corresponding GEDR status bit when a falling edge is detected on
the GPIO port