Chapter 17 Flash Memory
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A fourth case involves an attempted read access while the Flash array is busy doing a write (program) or
erase operation if the appropriate read-while-write control field is programmed for this response. The 3-bit
read-while-write control allows for immediate termination of an attempted read, or various
stall-while-write/erase operations are occurring.
The platform Flash controller can also terminate the current AHB access if hready_in is asserted before
the end of the current bus access. While this circumstance should not occur, this does not result in an error
condition being reported, as this behavior is initiated by the AHB. In this circumstance, the platform Flash
controller control state machine completes any Flash array access in progress (without signaling the AHB)
before handling a new access request.
17.2.12 Access pipelining
The platform Flash controller does not support access pipelining since this capability is not supported by
the Flash array. As a result, the APC (Address Pipelining Control) field should typically be the same value
as the RWSC (Read Wait State Control) field for best performance, that is, BK
n
_APC = BK
n
_RWSC. It
cannot be less than the RWSC.
17.2.13 Flash error response operation
The Flash array may signal an error response by asserting bk
n
_fl_xfr_err to terminate a requested access
with an error. This may occur due to an uncorrectable ECC error, or because of improper sequencing
during program/erase operations. When an error response is received, the platform Flash controller does
not update or validate a bank0 page read buffer nor the bank1 temporary holding register. An error
response may be signaled on read or write operations. For more information on the specifics related to
signaling of errors, including Flash ECC, refer to subsequent sections in this chapter. For additional
information on the system registers that capture the faulting address, attributes, data and ECC information,
see
Chapter 15, “Error Correction Status Module (ECSM).
17.2.14 Bank0 page read buffers and prefetch operation
The logic associated with bank0 of the platform Flash controller contains four 128-bit page read buffers
that hold data read from the Flash array. Each buffer operates independently, and is filled using a single
array access. The buffers are used for both prefetch and normal demand fetches.
The organization of each page buffer is described as follows in a pseudo-code representation. The
hardware structure includes the buffer address and valid bit, along with 128 bits of page read data and
several error flags.
struct {
// bk0_page_buffer
reg
addr[23:4];// page address
reg
valid;
// valid bit
reg
rdata[127:0];// page read data
reg
xfr_error;
// transfer error indicator from Flash array
reg
multi_ecc_error;// multi-bit ECC error indicator from Flash array
reg
single_ecc_error;// single-bit correctable ECC indicator from Flash array
}
bk0_page_buffer[4];
Содержание SAFE ASSURE Qorivva MPC5601P
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Страница 62: ...Chapter 2 MPC5602P Memory Map MPC5602P Microcontroller Reference Manual Rev 4 62 Freescale Semiconductor ...
Страница 104: ...Chapter 4 Clock Description MPC5602P Microcontroller Reference Manual Rev 4 104 Freescale Semiconductor ...
Страница 128: ...Chapter 6 Power Control Unit MC_PCU MPC5602P Microcontroller Reference Manual Rev 4 128 Freescale Semiconductor ...
Страница 272: ...Chapter 12 e200z0 and e200z0h Core MPC5602P Microcontroller Reference Manual Rev 4 272 Freescale Semiconductor ...
Страница 280: ...Chapter 14 Crossbar Switch XBAR MPC5602P Microcontroller Reference Manual Rev 4 280 Freescale Semiconductor ...
Страница 306: ...Chapter 16 Internal Static RAM SRAM MPC5602P Microcontroller Reference Manual Rev 4 306 Freescale Semiconductor ...
Страница 380: ...Chapter 17 Flash Memory MPC5602P Microcontroller Reference Manual Rev 4 380 Freescale Semiconductor ...
Страница 532: ...Chapter 21 LIN Controller LINFlex MPC5602P Microcontroller Reference Manual Rev 4 532 Freescale Semiconductor ...
Страница 578: ...Chapter 22 FlexCAN MPC5602P Microcontroller Reference Manual Rev 4 578 Freescale Semiconductor ...
Страница 708: ...Chapter 25 FlexPWM MPC5602P Microcontroller Reference Manual Rev 4 708 Freescale Semiconductor ...
Страница 742: ...Chapter 26 eTimer MPC5602P Microcontroller Reference Manual Rev 4 742 Freescale Semiconductor ...
Страница 760: ...Chapter 27 Functional Safety MPC5602P Microcontroller Reference Manual Rev 4 760 Freescale Semiconductor ...
Страница 782: ...Chapter 28 Fault Collection Unit FCU MPC5602P Microcontroller Reference Manual Rev 4 782 Freescale Semiconductor ...
Страница 788: ...Chapter 29 Wakeup Unit WKPU MPC5602P Microcontroller Reference Manual Rev 4 788 Freescale Semiconductor ...
Страница 798: ...Chapter 30 Periodic Interrupt Timer PIT MPC5602P Microcontroller Reference Manual Rev 4 798 Freescale Semiconductor ...
Страница 816: ...Chapter 32 Cyclic Redundancy Check CRC MPC5602P Microcontroller Reference Manual Rev 4 816 Freescale Semiconductor ...
Страница 848: ...Chapter 33 Boot Assist Module BAM MPC5602P Microcontroller Reference Manual Rev 4 848 Freescale Semiconductor ...
Страница 930: ...Chapter 36 Nexus Development Interface NDI MPC5602P Microcontroller Reference Manual Rev 4 930 Freescale Semiconductor ...