I have review i.MX27's spec, it is a good chip to dev a new high-end embedded EFTPOS, please do some work to support ISO7816 smartcard standard! eg. ATMEL AT91SAMs add 7816 compatible UART function to exist standard USARTs, it is not difficult but useful! If tapout a i.MX27L/S to drop H.264/H.263/ cameraI/F is so good, don't forgot big-pitch package to support six-layer PCB & industry temp range.