Completed PAL support for AT91SAM7X.

git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@1057 35acf78f-673a-0410-8e92-d51de3d6d3f4

11 files changed, 268 insertions, 42 deletions

diff --git a/demos/ARM7-AT91SAM7X-GCC/Makefile b/demos/ARM7-AT91SAM7X-GCC/Makefile
index 728167a6d..db19978c8 100644
--- a/demos/ARM7-AT91SAM7X-GCC/Makefile
+++ b/demos/ARM7-AT91SAM7X-GCC/Makefile
@@ -49,6 +49,7 @@ include ../../test/test.mk
 # C sources that can be compiled in ARM or THUMB mode depending on the global

 # setting.

 CSRC = ../../ports/ARM7/chcore.c \

+       ../../ports/ARM7-AT91SAM7X/pal_lld.c \

        ../../ports/ARM7-AT91SAM7X/sam7x_serial.c \

        ${KERNSRC} \

        ${TESTSRC} \

diff --git a/demos/ARM7-AT91SAM7X-GCC/board.c b/demos/ARM7-AT91SAM7X-GCC/board.c
index 02ac5046d..aac51cf0c 100644
--- a/demos/ARM7-AT91SAM7X-GCC/board.c
+++ b/demos/ARM7-AT91SAM7X-GCC/board.c
@@ -58,6 +58,15 @@ static CH_IRQ_HANDLER(SYSIrqHandler) {
 }

 

 /*

+ * Digital I/O ports static configuration as defined in @p board.h.

+ */

+static const AT91SAM7XPIOConfig config =

+{

+  {VAL_PIOA_ODSR, VAL_PIOA_OSR, VAL_PIOA_PUSR},

+  {VAL_PIOB_ODSR, VAL_PIOB_OSR, VAL_PIOB_PUSR}

+};

+

+/*

  * Early initialization code.

  * This initialization is performed just after reset before BSS and DATA

  * segments initialization.

@@ -100,7 +109,7 @@ void hwinit0(void) {
   /*

    * PIO initialization.

    */

-  palInit();

+  palInit(&config);

 }

 

 /*

@@ -126,24 +135,26 @@ void hwinit1(void) {
    * LCD pins setup.

    */

   palClearPad(IOPORT_B, PIOB_LCD_BL);

-  AT91C_BASE_PIOB->PIO_OER    = PIOB_LCD_BL_MASK;    // Configure as output.

-  AT91C_BASE_PIOB->PIO_PPUDR  = PIOB_LCD_BL_MASK;    // Disable internal pullup resistor.

+  palSetPadMode(IOPORT_B, PIOB_LCD_BL, PAL_MODE_OUTPUT_PUSHPULL);

 

   palSetPad(IOPORT_A, PIOA_LCD_RESET);

-  AT91C_BASE_PIOA->PIO_OER    = PIOA_LCD_RESET_MASK; // Configure as output.

-  AT91C_BASE_PIOA->PIO_PPUDR  = PIOA_LCD_RESET_MASK; // Disable internal pullup resistor.

+  palSetPadMode(IOPORT_A, PIOA_LCD_RESET, PAL_MODE_OUTPUT_PUSHPULL);

 

   /*

-   * Joystick and buttons, disable pullups, already inputs.

+   * Joystick and buttons setup.

    */

-  AT91C_BASE_PIOA->PIO_PPUDR = PIOA_B1_MASK | PIOA_B2_MASK | PIOA_B3_MASK |

-                               PIOA_B4_MASK | PIOA_B5_MASK;

-  AT91C_BASE_PIOB->PIO_PPUDR = PIOB_SW1_MASK | PIOB_SW2_MASK;

+  palSetGroupMode(IOPORT_A,

+                  PIOA_B1_MASK | PIOA_B2_MASK | PIOA_B3_MASK |

+                  PIOA_B4_MASK | PIOA_B5_MASK,

+                  PAL_MODE_INPUT);

+  palSetGroupMode(IOPORT_B, PIOB_SW1_MASK | PIOB_SW2_MASK, PAL_MODE_INPUT);

 

   /*

-   * MMC/SD slot, disable pullups, already inputs.

+   * MMC/SD slot setup.

    */

-  AT91C_BASE_SYS->PIOB_PPUDR = PIOB_MMC_WP_MASK | PIOB_MMC_CP_MASK;

+  palSetGroupMode(IOPORT_B,

+                  PIOB_MMC_WP_MASK | PIOB_MMC_CP_MASK,

+                  PAL_MODE_INPUT);

 

   /*

    * PIT Initialization.

diff --git a/demos/ARM7-AT91SAM7X-GCC/board.h b/demos/ARM7-AT91SAM7X-GCC/board.h
index fe9219aa3..c56f50258 100644
--- a/demos/ARM7-AT91SAM7X-GCC/board.h
+++ b/demos/ARM7-AT91SAM7X-GCC/board.h
@@ -20,9 +20,7 @@
 #ifndef _BOARD_H_

 #define _BOARD_H_

 

-#ifndef AT91SAM7X256_H

 #include "at91lib/AT91SAM7X256.h"

-#endif

 

 #define BOARD_OLIMEX_SAM7_EX256

 

@@ -30,6 +28,17 @@
 #define MCK             48054857

 

 /*

+ * Initial I/O setup.
+ */

+#define VAL_PIOA_ODSR           0x00000000      /* Output data. */

+#define VAL_PIOA_OSR            0x00000000      /* Direction. */

+#define VAL_PIOA_PUSR           0xFFFFFFFF      /* Pull-up. */

+

+#define VAL_PIOB_ODSR           0x00000000      /* Output data. */

+#define VAL_PIOB_OSR            0x00000000      /* Direction. */

+#define VAL_PIOB_PUSR           0xFFFFFFFF      /* Pull-up. */

+

+/*

  * I/O definitions.

  */

 #define PIOA_LCD_RESET          2

diff --git a/demos/ARM7-AT91SAM7X-WEB-GCC/Makefile b/demos/ARM7-AT91SAM7X-WEB-GCC/Makefile
index c9a08306a..4b0aad5a1 100644
--- a/demos/ARM7-AT91SAM7X-WEB-GCC/Makefile
+++ b/demos/ARM7-AT91SAM7X-WEB-GCC/Makefile
@@ -58,6 +58,7 @@ USRC = ../../ext/uip-1.0/uip/uip_arp.c \
 # C sources that can be compiled in ARM or THUMB mode depending on the global

 # setting.

 CSRC = ../../ports/ARM7/chcore.c \

+       ../../ports/ARM7-AT91SAM7X/pal_lld.c \

        ../../ports/ARM7-AT91SAM7X/sam7x_serial.c \

        ../../ports/ARM7-AT91SAM7X/sam7x_emac.c \

        ${KERNSRC} \

diff --git a/demos/ARM7-AT91SAM7X-WEB-GCC/board.c b/demos/ARM7-AT91SAM7X-WEB-GCC/board.c
index e0b170120..4557d3c91 100644
--- a/demos/ARM7-AT91SAM7X-WEB-GCC/board.c
+++ b/demos/ARM7-AT91SAM7X-WEB-GCC/board.c
@@ -59,6 +59,15 @@ static CH_IRQ_HANDLER(SYSIrqHandler) {
 }

 

 /*

+ * Digital I/O ports static configuration as defined in @p board.h.

+ */

+static const AT91SAM7XPIOConfig config =

+{

+  {VAL_PIOA_ODSR, VAL_PIOA_OSR, VAL_PIOA_PUSR},

+  {VAL_PIOB_ODSR, VAL_PIOB_OSR, VAL_PIOB_PUSR}

+};

+

+/*

  * Early initialization code.

  * This initialization is performed just after reset before BSS and DATA

  * segments initialization.

@@ -101,7 +110,7 @@ void hwinit0(void) {
   /*

    * PIO initialization.

    */

-  palInit();

+  palInit(&config);

 }

 

 /*

@@ -127,24 +136,26 @@ void hwinit1(void) {
    * LCD pins setup.

    */

   palClearPad(IOPORT_B, PIOB_LCD_BL);

-  AT91C_BASE_PIOB->PIO_OER    = PIOB_LCD_BL_MASK;    // Configure as output.

-  AT91C_BASE_PIOB->PIO_PPUDR  = PIOB_LCD_BL_MASK;    // Disable internal pullup resistor.

+  palSetPadMode(IOPORT_B, PIOB_LCD_BL, PAL_MODE_OUTPUT_PUSHPULL);

 

   palSetPad(IOPORT_A, PIOA_LCD_RESET);

-  AT91C_BASE_PIOA->PIO_OER    = PIOA_LCD_RESET_MASK; // Configure as output.

-  AT91C_BASE_PIOA->PIO_PPUDR  = PIOA_LCD_RESET_MASK; // Disable internal pullup resistor.

+  palSetPadMode(IOPORT_A, PIOA_LCD_RESET, PAL_MODE_OUTPUT_PUSHPULL);

 

   /*

-   * Joystick and buttons, disable pullups, already inputs.

+   * Joystick and buttons setup.

    */

-  AT91C_BASE_PIOA->PIO_PPUDR = PIOA_B1_MASK | PIOA_B2_MASK | PIOA_B3_MASK |

-                               PIOA_B4_MASK | PIOA_B5_MASK;

-  AT91C_BASE_PIOB->PIO_PPUDR = PIOB_SW1_MASK | PIOB_SW2_MASK;

+  palSetGroupMode(IOPORT_A,

+                  PIOA_B1_MASK | PIOA_B2_MASK | PIOA_B3_MASK |

+                  PIOA_B4_MASK | PIOA_B5_MASK,

+                  PAL_MODE_INPUT);

+  palSetGroupMode(IOPORT_B, PIOB_SW1_MASK | PIOB_SW2_MASK, PAL_MODE_INPUT);

 

   /*

-   * MMC/SD slot, disable pullups, already inputs.

+   * MMC/SD slot setup.

    */

-  AT91C_BASE_SYS->PIOB_PPUDR = PIOB_MMC_WP_MASK | PIOB_MMC_CP_MASK;

+  palSetGroupMode(IOPORT_B,

+                  PIOB_MMC_WP_MASK | PIOB_MMC_CP_MASK,

+                  PAL_MODE_INPUT);

 

   /*

    * PIT Initialization.

diff --git a/demos/ARM7-AT91SAM7X-WEB-GCC/board.h b/demos/ARM7-AT91SAM7X-WEB-GCC/board.h
index fe9219aa3..c56f50258 100644
--- a/demos/ARM7-AT91SAM7X-WEB-GCC/board.h
+++ b/demos/ARM7-AT91SAM7X-WEB-GCC/board.h
@@ -20,9 +20,7 @@
 #ifndef _BOARD_H_

 #define _BOARD_H_

 

-#ifndef AT91SAM7X256_H

 #include "at91lib/AT91SAM7X256.h"

-#endif

 

 #define BOARD_OLIMEX_SAM7_EX256

 

@@ -30,6 +28,17 @@
 #define MCK             48054857

 

 /*

+ * Initial I/O setup.
+ */

+#define VAL_PIOA_ODSR           0x00000000      /* Output data. */

+#define VAL_PIOA_OSR            0x00000000      /* Direction. */

+#define VAL_PIOA_PUSR           0xFFFFFFFF      /* Pull-up. */

+

+#define VAL_PIOB_ODSR           0x00000000      /* Output data. */

+#define VAL_PIOB_OSR            0x00000000      /* Direction. */

+#define VAL_PIOB_PUSR           0xFFFFFFFF      /* Pull-up. */

+

+/*

  * I/O definitions.

  */

 #define PIOA_LCD_RESET          2

diff --git a/demos/ARMCM3-STM32F103-GCC/board.c b/demos/ARMCM3-STM32F103-GCC/board.c
index 0f6c5be6b..25b88511f 100644
--- a/demos/ARMCM3-STM32F103-GCC/board.c
+++ b/demos/ARMCM3-STM32F103-GCC/board.c
@@ -32,7 +32,7 @@ static const STM32GPIOConfig config =
   {VAL_GPIOAODR, VAL_GPIOACRL, VAL_GPIOACRH},

   {VAL_GPIOBODR, VAL_GPIOBCRL, VAL_GPIOBCRH},

   {VAL_GPIOCODR, VAL_GPIOCCRL, VAL_GPIOCCRH},

-  {VAL_GPIODODR, VAL_GPIODCRL, VAL_GPIODCRH},

+  {VAL_GPIODODR, VAL_GPIODCRL, VAL_GPIODCRH}

 };

 

 /*

diff --git a/ports/ARM7-AT91SAM7X/pal_lld.c b/ports/ARM7-AT91SAM7X/pal_lld.c
new file mode 100644
index 000000000..266bdb38d
--- /dev/null
+++ b/ports/ARM7-AT91SAM7X/pal_lld.c
@@ -0,0 +1,116 @@
+/*

+    ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.

+

+    This file is part of ChibiOS/RT.

+

+    ChibiOS/RT is free software; you can redistribute it and/or modify

+    it under the terms of the GNU General Public License as published by

+    the Free Software Foundation; either version 3 of the License, or

+    (at your option) any later version.

+

+    ChibiOS/RT is distributed in the hope that it will be useful,

+    but WITHOUT ANY WARRANTY; without even the implied warranty of

+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+    GNU General Public License for more details.

+

+    You should have received a copy of the GNU General Public License

+    along with this program.  If not, see <http://www.gnu.org/licenses/>.

+*/

+

+/**

+ * @file ports/ARM7-AT91SAM7X/pal_lld.c

+ * @brief AT91SAM7X PIO low level driver code

+ * @addtogroup AT91SAM7X_PAL

+ * @{

+ */

+

+#include <ch.h>

+#include <pal.h>

+

+/**

+ * @brief AT91SAM7X I/O ports configuration.

+ * @details PIO registers initialization.

+ *

+ * @param[in] config the AT91SAM7X ports configuration

+ */

+void _pal_lld_init(const AT91SAM7XPIOConfig *config) {

+

+  AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_PIOA) | (1 << AT91C_ID_PIOB);

+

+  /*

+   * PIOA setup.
+   */

+  AT91C_BASE_PIOA->PIO_OER  = config->P0Data.pusr;      /* Pull-up as spec.*/

+  AT91C_BASE_PIOA->PIO_ODR  = ~config->P0Data.pusr;

+  AT91C_BASE_PIOA->PIO_PER  = 0xFFFFFFFF;               /* PIO enabled.*/

+  AT91C_BASE_PIOA->PIO_ODSR = config->P0Data.odsr;      /* Data as specified.*/

+  AT91C_BASE_PIOA->PIO_OER  = config->P0Data.osr;       /* Dir. as specified.*/

+  AT91C_BASE_PIOA->PIO_ODR  = ~config->P0Data.osr;

+  AT91C_BASE_PIOA->PIO_IFDR = 0xFFFFFFFF;               /* Filter disabled.*/

+  AT91C_BASE_PIOA->PIO_IDR  = 0xFFFFFFFF;               /* Int. disabled.*/

+  AT91C_BASE_PIOA->PIO_MDDR = 0xFFFFFFFF;               /* Push Pull drive.*/

+  AT91C_BASE_PIOA->PIO_ASR  = 0xFFFFFFFF;               /* Peripheral A.*/

+  AT91C_BASE_PIOA->PIO_OWER = 0xFFFFFFFF;               /* Write enabled.*/

+

+  /*

+   * PIOB setup.
+   */

+  AT91C_BASE_PIOB->PIO_OER  = config->P0Data.pusr;      /* Pull-up as spec.*/

+  AT91C_BASE_PIOB->PIO_ODR  = ~config->P0Data.pusr;

+  AT91C_BASE_PIOB->PIO_PER  = 0xFFFFFFFF;               /* PIO enabled.*/

+  AT91C_BASE_PIOB->PIO_ODSR = config->P1Data.odsr;      /* Data as specified.*/

+  AT91C_BASE_PIOB->PIO_OER  = config->P1Data.osr;       /* Dir. as specified.*/

+  AT91C_BASE_PIOB->PIO_ODR  = ~config->P1Data.osr;

+  AT91C_BASE_PIOB->PIO_IFDR = 0xFFFFFFFF;               /* Filter disabled.*/

+  AT91C_BASE_PIOB->PIO_IDR  = 0xFFFFFFFF;               /* Int. disabled.*/

+  AT91C_BASE_PIOB->PIO_MDDR = 0xFFFFFFFF;               /* Push Pull drive.*/

+  AT91C_BASE_PIOB->PIO_ASR  = 0xFFFFFFFF;               /* Peripheral A.*/

+  AT91C_BASE_PIOB->PIO_OWER = 0xFFFFFFFF;               /* Write enabled.*/

+}

+

+/**

+ * @brief Pads mode setup.

+ * @details This function programs a pads group belonging to the same port

+ *          with the specified mode.

+ *

+ * @param[in] port the port identifier

+ * @param[in] mask the group mask

+ * @param[in] mode the mode

+ *

+ * @note This function is not meant to be invoked directly by the application

+ *       code.

+ * @note @p PAL_MODE_RESET is implemented as input with pull-up.

+ * @note @p PAL_MODE_UNCONNECTED is implemented as push pull output with high

+ *       state.

+ * @note @p PAL_MODE_OUTPUT_OPENDRAIN also enables the pull-up resistor.

+ */

+void _pal_lld_setgroupmode(ioportid_t port,

+                           ioportmask_t mask,

+                           uint_fast8_t mode) {

+

+  switch (mode & PAL_MODE_MASK) {

+  case PAL_MODE_RESET:

+  case PAL_MODE_INPUT_PULLUP:

+    port->PIO_PPUER = mask;

+    port->PIO_ODR = mask;

+    break;

+  case PAL_MODE_INPUT:

+    port->PIO_PPUDR = mask;

+    port->PIO_ODR = mask;

+    break;

+  case PAL_MODE_UNCONNECTED:

+    port->PIO_SODR = mask;

+    /* Falls in */

+  case PAL_MODE_OUTPUT_PUSHPULL:

+    port->PIO_PPUDR = mask;

+    port->PIO_OER = mask;

+    port->PIO_MDDR = mask;

+    break;

+  case PAL_MODE_OUTPUT_OPENDRAIN:

+    port->PIO_PPUER = mask;

+    port->PIO_OER = mask;

+    port->PIO_MDER = mask;

+  }

+}

+

+/** @} */

diff --git a/ports/ARM7-AT91SAM7X/pal_lld.h b/ports/ARM7-AT91SAM7X/pal_lld.h
index 37088a4cc..b403fc2cc 100644
--- a/ports/ARM7-AT91SAM7X/pal_lld.h
+++ b/ports/ARM7-AT91SAM7X/pal_lld.h
@@ -19,7 +19,7 @@
 

 /**

  * @file ports/ARM7-AT91SAM7X/pal_lld.h

- * @brief AT91SAM7X PIO low level driver

+ * @brief AT91SAM7X PIO low level driver header

  * @addtogroup AT91SAM7X_PAL

  * @{

  */

@@ -27,15 +27,45 @@
 #ifndef _PAL_LLD_H_

 #define _PAL_LLD_H_

 

-#ifndef AT91SAM7X256_H

 #include "at91lib/AT91SAM7X256.h"

-#endif

+

+/*===========================================================================*/

+/* Unsupported modes and specific modes                                      */

+/*===========================================================================*/

+

+#undef PAL_MODE_INPUT_PULLDOWN

 

 /*===========================================================================*/

 /* I/O Ports Types and constants.                                            */

 /*===========================================================================*/

 

 /**

+ * @brief PIO port setup info.

+ */

+typedef struct {

+  /** Initial value for ODSR register (data).*/

+  uint32_t      odsr;

+  /** Initial value for OSR register (direction).*/

+  uint32_t      osr;

+  /** Initial value for PUSR register (Pull-ups).*/

+  uint32_t      pusr;

+} at91sam7x_pio_setup_t;

+

+/**

+ * @brief AT91SAM7X PIO static initializer.

+ * @details An instance of this structure must be passed to @p palInit() at

+ *          system startup time in order to initialized the digital I/O

+ *          subsystem. This represents only the initial setup, specific pads

+ *          or whole ports can be reprogrammed at later time.

+ */

+typedef struct {

+  /** @brief Port 0 setup data.*/

+  at91sam7x_pio_setup_t P0Data;

+  /** @brief Port 1 setup data.*/

+  at91sam7x_pio_setup_t P1Data;

+} AT91SAM7XPIOConfig;

+

+/**

  * @brief Width, in bits, of an I/O port.
  */

 #define PAL_IOPORTS_WIDTH 32

@@ -74,18 +104,8 @@ typedef AT91PS_PIO ioportid_t;
 

 /**

  * @brief Low level PAL subsystem initialization.

- * @details Clocks are enabled and both PIO ports are reset to a known state

- *          and all pads are enabled a digital I/Os.

- *

- * @note The other PIO registers are not modified, the PIOs are supposed to

- *       have just been reset. The PIO_PSR is cleared because its status

- *       after the reset is not very clear in the documentation.

  */

-#define pal_lld_init() {                                                \

-  AT91C_BASE_PMC->PMC_PCER = (1 << AT91C_ID_PIOA) | (1 << AT91C_ID_PIOB); \

-  AT91C_BASE_PIOA->PIO_PER  = 0xFFFFFFFF;                               \

-  AT91C_BASE_PIOB->PIO_PER  = 0xFFFFFFFF;                               \

-}

+#define pal_lld_init(config) _pal_lld_init(config)

 

 /**

  * @brief Reads the physical I/O port states.

@@ -181,6 +201,23 @@ typedef AT91PS_PIO ioportid_t;
 }

 

 /**

+ * @brief Pads group mode setup.

+ * @details This function programs a pads group belonging to the same port

+ *          with the specified mode.

+ *

+ * @param[in] port the port identifier

+ * @param[in] mask the group mask

+ * @param[in] mode the mode

+ *

+ * @note This function is not meant to be invoked directly by the application

+ *       code.

+ * @note @p PAL_MODE_UNCONNECTED is implemented as push pull output with high

+ *       state.

+ */

+#define pal_lld_setgroupmode(port, mask, mode) \

+  _pal_lld_setgroupmode(port, mask, mode)

+

+/**

  * @brief Writes a logical state on an output pad.

  *

  * @param[in] port the port identifier

@@ -192,6 +229,17 @@ typedef AT91PS_PIO ioportid_t;
  */

 #define pal_lld_writepad(port, pad, bit) pal_lld_writegroup(port, 1, pad, bit)

 

+#ifdef __cplusplus

+extern "C" {

+#endif

+  void _pal_lld_init(const AT91SAM7XPIOConfig *config);

+  void _pal_lld_setgroupmode(ioportid_t port,

+                             ioportmask_t mask,

+                             uint_fast8_t mode);

+#ifdef __cplusplus

+}

+#endif

+

 #endif /* _PAL_LLD_H_ */

 

 /** @} */

diff --git a/ports/ARM7-AT91SAM7X/port.dox b/ports/ARM7-AT91SAM7X/port.dox
index 245c4b4bc..dac6ed181 100644
--- a/ports/ARM7-AT91SAM7X/port.dox
+++ b/ports/ARM7-AT91SAM7X/port.dox
@@ -39,8 +39,21 @@
  * - Output latched regardless of the pad setting.

  * - Direct read of input pads regardless of the pad setting.

  * .

- * The only non atomic operations are bit toggling and bus/group writing.

+ * <h2>Supported Setup Modes</h2>

+ * - @p PAL_MODE_RESET.

+ * - @p PAL_MODE_UNCONNECTED.

+ * - @p PAL_MODE_INPUT.

+ * - @p PAL_MODE_INPUT_PULLUP.

+ * - @p PAL_MODE_OUTPUT_PUSHPULL.

+ * - @p PAL_MODE_OUTPUT_OPENDRAIN.

+ * .

+ * Any attempt to setup an invalid mode is ignored.

  *

+ * <h2>Suboptimal Behavior</h2>

+ * Some PIO features are less than optimal:

+ * - Pad/port toggling operations are not atomic.

+ * - Pad/group mode setup is not atomic.

+ * .

  * @ingroup AT91SAM7X

  */

 

diff --git a/src/lib/pal.h b/src/lib/pal.h
index c45a801e6..b75582ee1 100644
--- a/src/lib/pal.h
+++ b/src/lib/pal.h
@@ -28,6 +28,13 @@
 #define _PAL_H_

 

 /**

+ * @brief Bits in a mode word dedicated as mode selector.

+ * @details The other bits are not defined and may be used as device-specific

+ *          option bits.
+ */

+#define PAL_MODE_MASK                   0xF

+

+/**

  * @brief After reset state.

  * @details The state itself is not specified and is architecture dependent,

  *          it is guaranteed to be equal to the after-reset state. It is