MC9S12T64 Datasheet, PDF (242/608 Pages) Motorola, Inc – Specification

CALRAM 2K
Freescale Semiconductor, Inc.
Functional Description
The CALRAM is designed to replace data in the Flash EEPROM for
calibration purposes without stopping the user’s control program.
This function is controlled by the register INITCRM (see Module
Mapping Control (MMC) in page 121) and the CALCFG register.
Calibration Block
Specified by
INITCRM
CALRAM can be mapped to any 2K byte boundary within the 64K byte
memory space.
The CRAM[15:11] bits in the register INITCRM are used to map the
CALRAM to a 2K byte boundary. These write-anytime bits have to be
written in order to choose the calibration block area in the Flash
EEPROM. Since data in the CALRAM array is undefined after reset,
data may be written in the array before mapping to the calibration area
to prevent reading unpredictable values. Table 47 shows example
CALRAM mapping.
Table 47 Example CALRAM Mapping
CRAM[15:11]
00000
00001
00010
.....
11101
11110
11111
Address
$0000 – $07FF
$0800 – $0FFF
$1000 – $17FF
.....
$E800 – $EFFF
$F000 – $F7FF
$F800 – $FFFF
There is another bit called CRAMON in the register INITCRM. This
write-anytime bit makes the CALRAM array visible in the address
specified by the CRAM bits. If this bit is set the CALRAM is used,
otherwise the Flash memory is used.
Flash Super User
Mode Control
The FSUM bit in the register CALCFG determines if the Flash EEPROM
module enters the flash super user mode. When FSUM is set, the Flash
MC9S12T64Revision 1.1.1
CALRAM 2K
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