MC9S08RD32CFJE Freescale Semiconductor, MC9S08RD32CFJE Datasheet - Page 42

• Manufacturer Part Number: MC9S08RD32CFJE
• Description: IC MCU 32K FLASH 8MHZ 32-LQFP
• Manufacturer: Freescale Semiconductor
• Series: HCS08r

Specifications of MC9S08RD32CFJE

• Core Processor: HCS08
• Core Size: 8-Bit
• Speed: 8MHz
• Connectivity: SCI
• Peripherals: LVD, POR, PWM, WDT
• Number Of I /o: 25
• Program Memory Size: 32KB (32K x 8)
• Program Memory Type: FLASH
• Ram Size: 2K x 8
• Voltage - Supply (vcc/vdd): 1.8 V ~ 3.6 V
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 32-LQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Data Converters: -

Memory
Provided the key enable (KEYEN) bit is 1, the 8-byte comparison key can be used to temporarily
disengage memory security. This key mechanism can be accessed only through user code running in secure
memory. (A security key cannot be entered directly through background debug commands.) This security
key can be disabled completely by programming the KEYEN bit to 0. If the security key is disabled, the
only way to disengage security is by mass erasing the FLASH if needed (normally through the background
debug interface) and verifying that FLASH is blank. To avoid returning to secure mode after the next reset,
program the security bits (SEC01:SEC00) to the unsecured state (1:0).
4.3
The MC9S08RC/RD/RE/RG includes static RAM. The locations in RAM below $0100 can be accessed
using the more efficient direct addressing mode, and any single bit in this area can be accessed with the
bit-manipulation instructions (BCLR, BSET, BRCLR, and BRSET). Locating the most frequently
accessed program variables in this area of RAM is preferred.
The RAM retains data when the MCU is in low-power wait, stop2, or stop3 mode. At power-on or after
wakeup from stop1, the contents of RAM are uninitialized. RAM data is unaffected by any reset provided
that the supply voltage does not drop below the minimum value for RAM retention.
For compatibility with older M68HC05 MCUs, the HCS08 resets the stack pointer to $00FF. In the
MC9S08RC/RD/RE/RG, it is usually best to reinitialize the stack pointer to the top of the RAM so the
direct page RAM can be used for frequently accessed RAM variables and bit-addressable program
variables. Include the following 2-instruction sequence in your reset initialization routine (where RamLast
is equated to the highest address of the RAM in the Freescale-provided equate file).
When security is enabled, the RAM is considered a secure memory resource and is not accessible through
BDM or through code executing from non-secure memory. See
description of the security feature.
4.4
The FLASH memory is intended primarily for program storage. In-circuit programming allows the
operating program to be loaded into the FLASH memory after final assembly of the application product.
It is possible to program the entire array through the single-wire background debug interface. Because no
special voltages are needed for FLASH erase and programming operations, in-application programming
is also possible through other software-controlled communication paths. For a more detailed discussion of
in-circuit and in-application programming, refer to the HCS08 Family Reference Manual, Volume I,
Freescale Semiconductor document order number HCS08RMv1/D.
42
RAM
FLASH
LDHX
TXS
#RamLast+1
MC9S08RC/RD/RE/RG Data Sheet, Rev. 1.11
;point one past RAM
;SP<-(H:X-1)
Section 4.5,
“Security,” for a detailed
Freescale Semiconductor