PSD4235G2-90U STMicroelectronics, PSD4235G2-90U Datasheet - Page 77

• Manufacturer Part Number: PSD4235G2-90U
• Description: IC FLASH 4MBIT 90NS 80TQFP
• Manufacturer: STMicroelectronics

Specifications of PSD4235G2-90U

• Format - Memory: FLASH
• Memory Type: FLASH
• Memory Size: 4M (512K x 8)
• Speed: 90ns
• Interface: Parallel
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 80-TQFP, 80-VQFP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 497-1968

PSD4235G2
19.9
19.10
MMC2001
The Motorola MCORE MMC2001 MCU has a MOD input pin that selects interal or external
boot ROM. The PSD can be configured as the external flash boot ROM or as extension to
the internal ROM.
The MMC2001 has a 16-bit external data bus and 20 address lines with external chip select
signals. The Chip Select Control registers allow the user to customize the bus interface and
timing to fit the individual system requirement. A typical interface configuaration to the PSD
is shown in
EB0 and EB1 (enable byte-0 and enable byte-1) are connected to the CNTL1 (UDS) and
CNTL2 (LDS) pins. The WEN bit in the Chip Select Control register should be set to ’1’ to
terminate the EB0-EB1 earlier to provide the wrtie data hold time for the PSD. The WSC and
WWS bits in the Control register are set to wait states that meet the PSD access time
requirement.
Another option is to configure the EB0 and EB1 as WRL and WRH signals. In this case, the
PSD control setting will be: OE, WRL, WRH where OE is the READ signal for the
MMC2001.
C16x family
The PSD supports Infineon’s C16X family of MCUs (C161-C167) in both the multiplexed and
non-multiplexed bus configuration. In
PSD in a multiplexed bus configuration. The control signals from the MCU are WR, RD, BHE
and ALE, and are routed to the corresponding PSD pins.
The C167 has another control signal setting (RD, WRL, WRH, ALE) which is also supported
by the PSD.
Figure
24. The MMC2001’s R/W signal is conneced to the CNTL0 pin, while
Figure
25, the C167CR is shown connected to the
MCU bus interface
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