AT91SAM7SE256B-CU Atmel, AT91SAM7SE256B-CU Datasheet - Page 338

• Manufacturer Part Number: AT91SAM7SE256B-CU
• Description: IC ARM7 MCU FLASH 256K 144-LFBGA
• Manufacturer: Atmel
• Series: AT91SAMr

Specifications of AT91SAM7SE256B-CU

• Core Processor: ARM7
• Core Size: 16/32-Bit
• Speed: 55MHz
• Connectivity: EBI/EMI, I²C, SPI, SSC, UART/USART, USB
• Peripherals: Brown-out Detect/Reset, POR, PWM, WDT
• Number Of I /o: 88
• Program Memory Size: 256KB (256K x 8)
• Program Memory Type: FLASH
• Ram Size: 32K x 8
• Voltage - Supply (vcc/vdd): 1.65 V ~ 1.95 V
• Data Converters: A/D 8x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: *
• Core: ARM7TDMI
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Eeprom Size: -
• Lead Free Status / Rohs Status: Details

• PCS: Peripheral Chip Select
This field is only used if Fixed Peripheral Select is active (PS = 0).
If PCSDEC = 0:
If PCSDEC = 1:
• DLYBCS: Delay Between Chip Selects
This field defines the delay from NPCS inactive to the activation of another NPCS. The DLYBCS time guarantees non-over-
lapping chip selects and solves bus contentions in case of peripherals having long data float times.
If DLYBCS is less than or equal to six, six MCK periods will be inserted by default.
Otherwise, the following equation determines the delay:
338
PCS = xxx0
PCS = xx01
PCS = x011
PCS = 0111
PCS = 1111
(x = don’t care)
NPCS[3:0] output signals = PCS.
SAM7SE512/256/32 Preliminary
NPCS[3:0] = 1110
NPCS[3:0] = 1101
NPCS[3:0] = 0111
forbidden (no peripheral is selected)
NPCS[3:0] = 1011
Delay Between Chip Selects
=
DLYBCS
---------------------- -
MCK
6222F–ATARM–14-Jan-11